Why do my eyes hurt?

Summary

Mild eye pain can be a symptom of eyestrain or tiredness. The area around the eyes may also hurt during a migraine headache or sinus infection. In some cases, eye pain can also be a symptom of a more serious condition, such as uveitis.

The eyes can hurt in many different ways. A person may feel that their eyes are sore, aching, burning, or stinging, or that they have an object or other foreign body stuck in them.

This article will look at the potential causes of eye pain, some treatments and remedies, and when to see a doctor.

 

Causes

Looking at screens for an extended period of time may cause eyestrain.
Eyestrain
Eyestrain develops when the eyes get tired. This often occurs when someone is completing a task that involves focusing the eyes for long periods of time. This can result in aching, watery, or dry eyes.

Some potential causes of eyestrain include:

  • looking at screens
  • driving
  • reading
  • having exposure to bright lights

Resting the eyes can improve eyestrain. The National Eye Institute (NEI) recommend taking breaks from tasks such as reading every 20 minutes by looking at an object 20 feet away for 20 seconds.

Adjusting the brightness of screens, reducing glare from lights and windows, and taking regular breaks from driving may also help.

An incorrect prescription for eyeglasses can also cause eyestrain and headaches. Vision changes over time, so it is a good idea to undergo regular checkups with an eye doctor.

Dry eye

Dry eye is a common condition. It occurs when the tear ducts do not produce enough tears to keep the eyes moist.

Some symptoms of dry eye include:

  • scratchy eyes
  • burning or stinging eyes
  • sensitivity to light
  • blurry vision
  • redness

Dry eye is most likely to affect older adults, females, and people who do not get enough vitamin A or omega-3 fatty acids in their diet. People with certain autoimmune conditions, such as lupus or Sjogren’s syndrome, are also likely to develop dry eye.

Dry eye can also occur if someone spends a long time looking at a screen, as they may not blink as often. Air conditioning, smoke, and wind can also exacerbate this condition.

Treatment for dry eye includes hydrating eye drops and prescription medication that causes the body to make more tears. Undergoing a medical procedure to block the tear ducts can help if the cause of dry eye is tear ducts that drain too quickly.

Pink eye

Pink eye, or conjunctivitis, results from a virus or bacterium. The most common symptoms are:

  • pink or red eyes
  • itching or burning
  • watery eyes
  • discharge, which could be white, yellow, or green

Viral conjunctivitis usually resolves on its own without treatment. However, people with bacterial conjunctivitis may need antibiotic eye drops or eye ointment.

People with severe or persistent symptoms, and those who notice conjunctivitis symptoms in a newborn baby, should see a doctor.

It is easy to pass pink eye to other people. Therefore, anyone with symptoms of conjunctivitis should wash their hands regularly, especially after touching the eye area. It is also a good idea to temporarily:

  • stop wearing contact lenses
  • stop wearing eye makeup
  • stop sharing towels and other personal items
  • avoid swimming pools

People will be able to resume these activities when the infection has cleared up.

Fungal infection

Fungi can also cause eye infections.

People who work on farms or in gardens, plus those who wear contact lenses, have a higher risk of developing fungal eye infections. People with weaker immune systems, diabetes, and conditions that require corticosteroid treatment may also be more susceptible.

A fungal eye infection can cause:

  • eye pain
  • redness
  • blurred vision
  • sensitivity to light
  • tearing
  • discharge

It is important to seek medical treatment right away for these symptoms. According to the Centers for Disease Control and Prevention (CDC), all types of fungal eye infection require prescription medication. Treatment may involve antifungal eye drops, medication, or, in some cases, surgery.

Scratched cornea

The cornea is the clear layer of film that covers the front of the eye. A person may scratch their cornea when putting in contact lenses, applying makeup, or rubbing their eyes. The result is eye pain, along with:

  • a feeling that something is stuck in the eye
  • red, watery eyes
  • sensitivity to light
  • blurry vision

To treat a scratched cornea, a doctor may prescribe eye drops, a patch to protect the eye, or a special contact lens that can speed up healing.

According to the American Academy of Ophthalmology, mild scratches do not need treatment and will usually heal within 2 days. A larger scratch may take up to 1 week to heal.

Uveitis

According to the NEI, uveitis is a term that describes a range of inflammatory eye conditions. Uveitis can destroy eye tissue and may cause vision loss.

The symptoms include:

  • eye pain
  • blurry vision
  • dark, floating spots in vision
  • sensitivity to light
  • redness

The cause of uveitis is not always clear. It may develop due to an eye injury, infection, tumor, or autoimmune condition. It can be an acute condition that goes away or a chronic condition that reoccurs.

Uveitis needs medical attention. Treatment is usually with prescription eye drops or medication. The aim is to reduce pain and inflammation, prevent tissue damage, and restore vision.

 

Eye pain and other symptoms

If eye pain occurs alongside other symptoms, it may indicate that the person has a different condition causing their eye pain.

Potential conditions include:

  • Sinus infection: Pain that affects the cheeks, forehead, and eyes, along with a blocked nose and fever, may indicate a sinus infection. A doctor can treat a sinus infection with antibiotics.
  • Migraine: Migraine is a condition that causes severe headaches, often on one side of the head. Migraine may cause a sharp pain in or behind the eyes or brow bone, sensitivity to light, and nausea or vomiting.
  • Cervicogenic headache: This type of headache can cause pain around the eyes, on one side of the face or head, and in the neck or shoulders. Nausea, blurred vision, and sensitivity to light or sound can also occur.
Home remedies

Home remedies cannot cure serious eye conditions or infections, such as a fungal infection or uveitis. However, they can provide symptom relief for people with tired, sore, or dry eyes.

Some home remedies include:

  • Resting: Eye pain due to strain and an incorrect prescription can ease when a person rests their eyes. Taking regular breaks from reading or screen work may prevent eyestrain.
  • Using a humidifier: Humidifiers can increase the moisture in the air, which can help people with dry eyes and those who live in dry climates.
  • Trying over-the-counter drops: Hydrating eye drops add moisture to the eyes and can help people with tired or dry eyes feel better.
  • Reducing exposure to irritants: Smoke, high winds, and air conditioning can exacerbate eye dryness. If possible, it may help someone to reduce their exposure to these irritants.
    Stopping smoking: Cigarette smoke irritates the eyes. According to the NEI, smoking also increases the risk of eye disease and optic nerve damage.

The NEI recommend reducing the risk of eye conditions by eating dark, leafy greens, oily fish such as salmon and halibut, and foods that contain vitamin A, such as carrots and broccoli.

 

When to see a doctor

If a person’s eye pain is severe, persistent, or accompanied by other symptoms — such as pus or sensitivity to light — they should see a doctor. Any loss of vision is also a reason to seek medical advice.

People at risk of developing eye disease or complications should also see an optician if they experience any eye pain. This includes people with diabetes, high blood pressure, and conditions that weaken the immune system.

Newborn babies can develop serious conditions as a result of eye infections. Parents and caregivers should take infants with puffy eyelids, red eyes, or eye discharge to a doctor right away.

Summary

Mild eye pain and discomfort are common. These symptoms can develop due to eyestrain or dryness, both of which can occur when someone spends a long period of time focusing the eyes on screens or books.

More severe eye pain may occur due to migraine, a scratched cornea, or an infection. If possible, a person should speak to a doctor about their symptoms.

 

Sources:

https://www.medicalnewstoday.com/articles/why-do-my-eyes-hurt#seeing-a-doctor

Dry EyeEye Health / BlindnessHeadache / Migraine
9 sourcesexpanded

Boyd, K. (2020). Corneal abrasion and erosion.
https://www.aao.org/eye-health/diseases/what-is-corneal-abrasion
Conjunctivitis (pink eye). (2019).
https://www.cdc.gov/conjunctivitis/
Dry eye. (2019).
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye
Fungal eye infections. (2017).
https://www.cdc.gov/fungal/diseases/fungal-eye-infections/index.html
Keep your eyes healthy. (2020).
https://www.nei.nih.gov/learn-about-eye-health/healthy-vision/keep-your-eyes-healthy
Pink eye. (2019).
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/pink-eye
The complete headache chart. (n.d.).

Uveitis. (2019).
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/uveitis
Vimont, C. (2020). Eye strain: How to prevent tired eyes.
https://www.aao.org/eye-health/diseases/what-is-eye-strain


Hayfever – a guide to looking after your eyes

The hay fever season runs from spring through to autumn and affects nearly 18 million people in the UK. Hay fever sufferers have allergic reactions to different types of pollen, which include itchy eyes and nose, sneezing, runny or blocked nose and difficulty in breathing. Pollen grains can set off an allergic reaction as the conjunctiva (the transparent membrane covering the white of the eye) becomes inflamed causing watery, red, itchy eyes. The whites of your eyes may swell up and you may also experience a gritty feeling in your eyes.

Managing your hay fever:
  • Stay indoors – when there is a high pollen count, keep windows and doors closed and keep surfaces clear with a damp duster. Avoid going out in the early evening and midmorning when the pollen count is at its highest.
  • Wear sunglasses when you are outdoors – wraparound glasses offer more protection from pollen.
  • Wear glasses rather than your contact lenses – especially when the pollen count is high.
  • Change your clothes and have a shower – if you have been outside for a while, you may have pollen on your clothes, skin and hair. Taking a shower and changing your clothes can help.
    Bathe your eyes regularly in cold water.
  • Apply petroleum jelly to your nostrils – this will trap pollen.

 

Treating your hay fever:
  • Anti-allergy eye drops – these act as a protective defence. If you wear contact lenses remember to check if you can use the drops while your lenses are in. The College has produced an infographic which gives guidance on the best time to start taking eye drops depending on your allergy.
  • Antihistamines – in people with allergies, the body mistakes something harmless, such as pollen, for a threat and produces histamine, which causes symptoms such as rashes, a runny nose and/or sneezing. Taking Antihistamines before you come into contact with pollen can prevent this happening or can help reduce the severity of the symptoms if taken afterwards.
  • Steroid eye drops – these are very effective but can have serious side effects, such as glaucoma, cataracts and damage to the cornea. They are only available on prescription.

Source:

College of Optometrists website . Lookafter your eyes – Hay fever


Looking after your mental health during the coronavirus outbreak

 

The Mental Health Foundation is part of the national mental health response during the coronavirus outbreak. Government advice designed to keep us safe is under constant review and will be different depending on where you live: more details and up to date information here.
Infectious disease outbreaks, like the current coronavirus (COVID-19), can be scary and can affect our mental health. While it is important to stay informed, there are also many things we can do to support and manage our wellbeing during such times.

Here are some tips we hope will help you, your friends and your family to look after your mental health at a time when there is much discussion of potential threats to our physical health.

Looking after your mental health as lockdown eases

Across the nations of the UK, lockdown is easing in different ways and at different times. As we begin to come out of lockdown many of us are faced with both challenges and opportunities.

Within social distancing guidelines, we may be able to see friends and family in person, play sport or return to work.

However, many of us may find even these longed-for changes difficult for our mental health. The idea of coming out of lockdown when the scientific debate is ongoing may also be worrying for those of us who are more at risk from the virus or living with mental health problems.

If this is something you are struggling with, read our tips on dealing with fear and anxiety as lockdown eases and coping with uncertainty.

People who are shielding – asked to still stay at home

For people who are shielding not much has changed. Lockdown still applies, with some ability to increase exercise, and to get outside with social distancing. For these groups in particular it might be difficult to see their lives returning to anything like ‘normal’ for a much longer time. As other people come out of lockdown the impact of lockdown on those who are shielding may become even greater.

As different at risk and shielding groups are told they are able to resume activities, people will need to make assessments of how safe things feel for them, and how they balance the risk to their wellbeing of remaining locked down against the risk of getting the virus if they resume activities.

Looking after your mental health while you have to stay at home

More of us will be spending a lot of time at home and many of our regular social activities will no longer be available to us.

It will help to try and see it as a different period in your life, and not necessarily a bad one, even if you didn’t choose it.

It will mean a different rhythm of life, a chance to be in touch with others in different ways than usual. Be in touch with other people regularly on social media, e-mail or on the phone, as they are still good ways of being close to the people who matter to you.

Create a new daily routine that prioritises looking after yourself. You could try reading more or watching movies, having an exercise routine, trying new relaxation techniques, or finding new knowledge on the internet. Try and rest and view this as a new if unusual experience, that might have its benefits.

Make sure your wider health needs are being looked after such as having enough prescription medicines available to you.

Try to avoid speculation and look up reputable sources on the outbreak

Rumour and speculation can fuel anxiety. Having access to good quality information about the virus can help you feel more in control.

Follow hygiene advice such as washing your hands more often than usual, for 20 seconds with soap and hot water (sing ‘happy birthday’ to yourself twice to make sure you do this for 20 seconds). You should do this whenever you get home or into work, blow your nose, sneeze or cough, eat or handle food. If you can’t wash your hands straightaway, use hand sanitiser and then wash them at the next opportunity.

You should also use tissues if you sneeze and make sure you dispose of them quickly; and stay at home if you are feeling unwell.

Try to stay connected

The way we are able to connect to others is changing, but this is happening at a different pace depending on who you are and where you live. Advice is significantly different if you are shielding, and you still need to take extra care if you have a long-term physical health condition, are pregnant or aged over 70.

There is a summary of how you can connect here

At times of stress, we work better in company and with support. Try and keep in touch with your friends and family, by telephone, email or social media, or contact a helpline for emotional support.

You may like to focus on the things you can do if you feel able to:

  • stress management
  • keep active
  • eat a balanced diet

Stay in touch with friends on social media but try not to sensationalise things. If you are sharing content, use this from trusted sources, and remember that your friends might be worried too.

Also remember to regularly assess your social media activity. Tune in with yourself and ask if they need to be adjusted. Are there particular accounts or people that are increasing your worry or anxiety? Consider muting or unfollowing accounts or hashtags that cause you to feel anxious.

Talk to your children

Involving our family and children in our plans for good health is essential. We need be alert to and ask children what they have heard about the outbreak and support them, without causing them alarm.

We need to minimise the negative impact it has on our children and explain the facts to them. Discuss the news with them but try and avoid over-exposure to coverage of the virus. Be as truthful as possible.

Let’s not avoid the ‘scary topic’ but engage in a way that is appropriate for them. We have more advice on talking with your children about the coronavirus outbreak.

Try to anticipate distress

It is OK to feel vulnerable and overwhelmed as we read news about the outbreak, especially if you have experienced trauma or a mental health problem in the past, or if you are shielding, have a long-term physical health condition or fall into one of the other groups that makes you more vulnerable to the effects of the coronavirus.

It’s important to acknowledge these feelings and remind each other to look after our physical and mental health. We should also be aware of and avoid increasing habits that may not be helpful in the long term, like smoking, drinking and overeating.

Try and reassure people you know who may be worried and check in with people who you know are living alone.

Try not to make assumptions

Don’t judge people and avoid jumping to conclusions about who is responsible for the spread of the disease. The coronavirus can affect anyone, regardless of gender, ethnicity or sex.

Try to manage how you follow the outbreak in the media

There is extensive news coverage about the outbreak. If you find that the news is causing you huge stress, it’s important to find a balance.

It’s best that you don’t avoid all news and that you keep informing and educating yourself, but limit your news intake if it is bothering you.

Source:

https://www.mentalhealth.org.uk/coronavirus/looking-after-your-mental-health-during-coronavirus-outbreak


Aritificial intelligence used to develop an early warning system for AMD

Researchers at Moorfields Eye Hospital and UCL Institute of Ophthalmology have developed an artificial intelligence (AI) system that can help predict whether people with age-related macular degeneration (AMD) will develop the more serious form of the condition in their ‘good eye’. This is part of our wider, ongoing partnership with DeepMind and Google Health.

AMD involves damage to the macula, the central part of the retina at the back of the eye. AMD causes loss of central vision, affecting the ability to read, drive, watch television, recognise faces, and many other activities of daily living. It is very common that patients develop wet AMD in one eye and start receiving treatment, before later developing it in their other eye.

Macular degeneration mainly affects central vision, causing “blind spots” directly ahead (Macular Society).

 

The AI system developed by Moorfields, researchers from DeepMind, and Google Health, may allow closer monitoring of the “good eye” in patients at high risk, or even guide use of preventative treatments in the future.

Pearse Keane, consultant ophthalmologist at Moorfields Eye Hospital, said:

“Patients who have lost vision from wet AMD are often particularly worried that their “good eye” will become affected and, as a result, that they will become blind. We hope that this AI system can be used as an early warning system for this condition and thus help preserve sight.”

“We are already beginning to think about how this will let us plan clinical trials of preventative therapies – for example, by treating eyes at high risk earlier.”

“With this work, we haven’t solved AMD, but we believe we have found another big piece of the puzzle.”

Reena Chopra, research optometrist at Moorfields Eye Hospital, said:

“We found that the ophthalmologists and optometrists in our study had some intuition into which eyes will progress to wet AMD. The AI was able to outperform them, indicating there are signals within OCT scans that only the AI can detect. This unlocks new areas of research into a disease where there are still many unanswered questions about how it develops.”

Source:

Read the paper in Nature Medicine.

Read the Google Health blog and DeepMind technical blog.


Eye Health: The Importance of Protecting Your Eyes

UV PROTECTION


UV rays can lead to serious health issues including sunburn of the eyes, cataracts, macular degeneration and cancer.

All Maui Jim lenses block 100% of all harmful UV rays, protecting your eyes from damage and long-term health risks. Sunglasses that do not provide UV protection can actually cause more damage because they shade the eye, allowing for more UV rays to hit the pupil.

 

SKIN CANCER


5% to 10% of skin cancer occurs around the eyes. Always wear quality, protective sunglasses when outdoors—even on overcast days.

Our sunglasses have earned the Skin Cancer Foundation Seal of Recommendation as an effective UV filter for the eyes and surrounding skin. The frames also play a role, so larger frames and wrap styles should be considered for outdoor activities.

 

EYE COMFORT & GLARE


The sun’s brightness and glare interferes with comfortable vision and the ability to see clearly, causes squinting, and your eyes to water. Eyestrain can also lead to headaches.

All Maui Jim sunglasses are polarised and therefore eliminate 99.9% of glare. This also reduces the impact of the sun’s brightness and allows your eyes to stay relaxed. Without the need to squint and strain, you can avoid eye fatigue, excessive wrinkling around the eyes, and even headaches.

 

DARK ADAPTATION

Intense sunlight can hamper the eyes’ ability to adapt quickly to lower light levels. Think about when you’re outside in bright light and not wearing sunglasses, then go indoors where the light is much dimmer; you see spots for a while until your eyes adjust.

By shielding your eyes from intense sunlight with our lenses, your eyes have a chance to gain faster adaptations when going from one extreme light condition to the next.

 

BLUE LIGHT PROTECTION


High-Energy Visible Radiation (HEV), also known as blue light, has lower energy rays than UV. However, recent research suggests they can penetrate the eye, and this has been associated with AMD (age-related macular degeneration).

Our patented PolarizedPlus2® lens technology reduces HEV without removing the beautiful visible blues colours from the world around you.

Source: Maui Jim Eye Health (https://www.mauijim.com/GB/en_GB/eyehealth)


How Does the Eye Work?

The human eye is a wonder of engineering. It consists of many different parts that work together to provide visual information to the brain, which then translates it into information that is useful to the body.

Parts of the eye

1. The cornea

The first step in this complex process occurs when light passes through the clear slightly convex cornea at the very front of the eye. This is the transparent part of the eyeball.

A thick white sheath called the sclera surrounds the rest of the eyeball. The cornea refracts light slightly. The narrow, liquid-filled space behind the cornea is called the aqueous humor. This drains through spaces at the medial corner of the eye, and is constantly renewed.

2. The iris

The iris is a colored diaphragm of thin circular and longitudinal muscle fibers just behind the cornea. It has an aperture in the center. This can expand or contract to let in more or less light, respectively, depending on the light in the surroundings.

This opening is called the pupil. Light passing through the cornea and the pupil falls on the anterior surface of the lens. The aqueous humor keeps the iris from sticking to the lens behind and the cornea in front.

3. The lens

The lens is a clear crystalline globe which almost touches the posterior surface of the pupillary opening. The ciliary muscles are attached to the surface of the lens. The help the lens to change shape in order to focus.

As they contract, they cause the lens to become more round or long, so that the rays bend more or less, according to need. If the object focused on is far away, the lens needs to bend the light rays from it more sharply, to make them fall on the center of the retina, where vision is sharpest. For objects close-up, the lens becomes elongated so that light rays are bent less.

4. The posterior chamber

The refracted rays now pass through the jelly-like tissue that fills out the eyeball behind the lens. This part is called the posterior chamber. At the back, the eyeball is bounded by the choroid, a network of capillaries which nourishes all the structures of the eye.

In front of it lies the retinal pigment epithelium, a layer of melanin-rich cells which supplies special nutrition to the sensory layer of the eye. The retina is nourished and renewed by the pigment epithelial cells.

5. The retina

The retina is a multilayer membrane comprising a sensory photoreceptor array, a few layers of connecting neurons and an inner ganglion cell layer. The axons from the ganglion cells travel backward to pierce the retina and leave the eye through the optic nerve. There is a blind spot in the retina where the ganglion cells pass through.

Rods and cones

The photoreceptors in the eye consist of rod and cone cells. The rods are found mostly in the peripheral part of the retina and are responsible for perception of light and dark, including shades of gray. They are more numerous than cones, and are very sensitive to light.

The cone cells are responsible for visual acuity and color vision, and millions of them are closely assembled in the central part of the retina, also called the macula. At the fovea, which is the central point of the macula, only cones are present, and normal vision uses this point to achieve sharp vision at maximum resolution.

The pathway of vision
As the light rays fall on the photoreceptor cells, changes occur in the pigments they contain. This leads to bleaching of the pigments, and electrical impulses are generated. These are transmitted through a chain of neurons to the ganglion cells which carry the impulses to the visual cortex of the brain. There they are processed and the object is seen.

Each eye receives information from half of the visual field. Thus the middle parts of both fields overlap, and this leads to binocular vision. However, the difference in the peripheral parts of the left and right fields of vision lead to depth perception or three-dimensional vision. It helps in gauging distances accurately and estimating the depths and dimensions of objects.

Sources:

The Structure and Function of the Eyes, www.merckmanuals.com/…/structure-and-function-of-the-eyes
Healthy Eyes Facts, https://nei.nih.gov/health/healthyeyes
Eye and its Function, http://www.pages.drexel.edu/~dh329/bmes212/eyeFunction.html
Last Updated: Feb 26, 2019

Written by Dr. Liji Thomas


What to know about computer vision syndrome

Computer vision syndrome (CVS) is the term for a group of eye and vision-related problems that develop following the prolonged use of devices with digital screens.

Devices such as computers, tablets, and smartphones put increased demands on a person’s visual system. Using these devices for extended periods without breaks can cause CVS symptoms, including eye strain and headaches.

In this article, we explain what CVS is and outline its causes and symptoms. We also provide tips on how to avoid CVS and when to see an optometrist.

What is it?

The extended use of devices with screens may lead to eye strain and headaches.
CVS describes a group of symptoms that occur following the prolonged use of devices with digital screens. Such devices include:

  • personal computers
  • laptops
  • tablets
  • smartphones

Common symptoms of CVS include eye strain and headaches. A person may also experience neck and shoulder pain as a result of sitting for long periods.

It is not clear how much time a person needs to spend looking at a digital screen to develop CVS. However, according to the American Optometric Association (AOA), longer periods of screen use seem to correlate with higher levels of discomfort.

Causes

Computer vision syndrome occurs as a result of prolonged digital screen use.

Digital screens cause a person’s eyes to work harder than normal. Several factors are responsible for this, including:

  • the screen content being less sharp or focused
  • poor contrast of the screen’s content against its background
  • reflections or glare bouncing off the screen

The following factors may also contribute to CVS:

  • viewing the screen in low light conditions
  • being too close to or too far from the screen
  • positioning the screen at an angle that causes eye strain
  • taking insufficient screen breaks

Together, these factors put greater demands on the eyes’ ability to track and focus. These demands are even higher for people who have minor uncorrected vision problems.

If the additional demands on the visual system occur over extended periods, a person may experience symptoms of CVS.

Symptoms

The symptoms of CVS may differ from one person to another. Some common symptoms include:

  • eye strain
  • dry and itchy eyes
  • blurry vision
  • double vision
  • difficulty focusing
  • nearsightedness, also called myopia
  • headaches
  • neck or shoulder pain and stiffness
  • backache

Treatment

The symptoms of CVS will usually go away after a sufficient break from screen use.

However, people who have underlying eye or vision problems will need to treat these problems to prevent future episodes of CVS. Some potential treatment options include those below.

Regular eye examinations

People who do not visit their optician regularly may have undiagnosed vision problems that worsen as a result of prolonged screen use. Others may be using outdated prescription glasses or lenses that are no longer effective in correcting their vision problems.

Regular visits to an optician can reduce the risk of CVS and other vision problems.

Vision therapy

Vision therapy is a form of therapy that aims to develop or improve a person’s vision. It involves the use of eye exercises to improve eye movement and focusing.

Vision therapy may be an option for people who continue to experience CVS and other vision problems despite wearing corrective glasses or contact lenses.

Laser eye surgery

Some people with underlying vision problems may be good candidates for laser eye surgery. This procedure uses lasers to reshape the surface of the eye so that it can focus more effectively.

Prevention

The best way to prevent CVS is to avoid long and uninterrupted periods of digital screen use. However, this is not an option for many people who work at a computer.

The AOA recommend following the 20-20-20 rule when working at a computer. Doing this involves taking a 20-second break every 20 minutes to view something that is 20 feet away. Following the 20-20-20 rule can reduce eye strain from digital screen use.

Other tips for preventing the symptoms of CVS include:

  • positioning the screen at the optimal distance, which will be about 20–28 inches from the eyes
  • positioning the screen at a comfortable angle, with the center of the screen 15–20 degrees below eye level
  • ensuring that there is adequate lighting
  • using an antiglare screen or changing the angle of the screen to avoid glare from lighting
  • remembering to blink regularly enough to avoid eye dryness
  • wearing glasses or lenses to correct any underlying vision problems, where necessary
  • sitting comfortably with both feet flat on the floor and support in place for the arms while typing
  • taking regular rest breaks

When to see an optometrist

In many cases, the symptoms of CVS will go away once a person has spent sufficient time away from digital screens.

To prevent future episodes of CVS, a person should take steps to improve their work environment and adopt healthful screen-management habits.

A person should visit their optician if they continue to experience CVS symptoms despite making the necessary changes to their screen use. Persistent symptoms can sometimes be a sign of an underlying eye condition that requires appropriate treatment.

Summary

Computer vision syndrome describes a group of symptoms that can arise as a result of prolonged screen use. Common symptoms of CVS include eye strain and headaches.

CVS can affect anyone who looks at a computer, tablet, or smartphone screen for long periods without breaks. However, it is particularly prevalent among people who have underlying vision problems.

The symptoms of CVS tend to subside once a person has taken a sufficient break from viewing digital screens. People can prevent future episodes by creating a comfortable work environment and adopting habits to maintain good eye health. Following the 20-20-20 rule is an effective way to reduce the risk of eye strain.

 

Source:

www.medicalnewstoday.com/articles/computer-vision-syndrome#summary

20/20/20 to prevent digital eye strain. (2016).
https://www.aoa.org/documents/infographics/SaveYourVisionMonth2016-1.pdf
Computer vision syndrome. (n.d.).
https://www.aoa.org/patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome
Laser eye surgery and lens surgery. (2020).
https://www.nhs.uk/live-well/healthy-body/laser-eye-surgery/
Loh, K. Y., & Redd, S. C. (2008). Understanding and preventing computer vision syndrome.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4170366/
Tran, K., & Ryce, A. (2018). Laser refractive surgery for vision correction: A review of clinical effectiveness and cost-effectiveness.
https://www.ncbi.nlm.nih.gov/books/NBK532537/
Vision therapy. (2016).
https://aapos.org/glossary/vision-therapy


World’s first spherical artificial eye has 3D retina

 

An international team led by scientists at the Hong Kong University of Science and Technology (HKUST) has recently developed the world’s first 3D artificial eye with capabilities better than existing bionic eyes and in some cases, even exceed those of the human eyes, bringing vision to humanoid robots and new hope to patients with visual impairment.

Scientists have spent decades trying to replicate the structure and clarity of a biological eye, but vision provided by existing prosthetic eyes — largely in the form of spectacles attached with external cables, are still in poor resolution with 2D flat image sensors. The Electrochemical Eye (EC-Eye) developed at HKUST, however, not only replicates the structure of a natural eye for the first time, but may actually offer sharper vision than a human eye in the future, with extra functions such as the ability to detect infrared radiation in darkness.

The key feature allowing such breakthroughs is a 3D artificial retina — made of an array of nanowire light sensors which mimic the photoreceptors in human retinas. Developed by Prof. FAN Zhiyong and Dr. GU Leilei from the Department of Electronic and Computer Engineering at HKUST, the team connected the nanowire light sensors to a bundle of liquid-metal wires serving as nerves behind the human-made hemispherical retina during the experiment, and successfully replicated the visual signal transmission to reflect what the eye sees onto the computer screen.

In the future, those nanowire light sensors could be directly connected to the nerves of the visually impaired patients. Unlike in a human eye where bundles of optic nerve fibers (for signal transmission) need to route through the retina via a pore — from the front side of the retina to the backside (thus creating a blind spot in human vision) before reaching the brain; the light sensors that now scatters across the entire human-made retina could each feed signals through its own liquid-metal wire at the back, thereby eliminating the blind spot issue as they do not have to route through a single spot.

Apart from that, as nanowires have even higher density than photoreceptors in human retina, the artificial retina can thus receive more light signals and potentially attain a higher image resolution than human retina — if the back contacts to individual nanowires are made in the future. With different materials used to boost the sensors’ sensitivity and spectral range, the artificial eye may also achieve other functions such as night vision.

“I have always been a big fan of science fiction, and I believe many technologies featured in stories such as those of intergalactic travel, will one day become reality. However, regardless of image resolution, angle of views or user-friendliness, the current bionic eyes are still of no match to their natural human counterpart. A new technology to address these problems is in urgent need, and it gives me a strong motivation to start this unconventional project,” said Prof. Fan, whose team has spent nine years to complete the current study from idea inception.

The team collaborated with the University of California, Berkeley on this project and their findings were recently published in the journal Nature.

“In the next step, we plan to further improve the performance, stability and biocompatibility of our device. For prosthesis application, we look forward to collaborating with medical research experts who have the relevant expertise on optometry and ocular prosthesis,” Prof. Fan added.

The working principle of the artificial eye involves an electrochemical process which is adopted from a type of solar cell. In principle, each photo sensor on the artificial retina can serve as a nanoscale solar cell. With further modification, the EC-Eye can be a self-powered image sensor, so there is no need for external power source nor circuitry when used for ocular prosthesis, which will be much more user-friendly as compared with the current technology.

Story Source:

Materials provided by Hong Kong University of Science and Technology. Note: Content may be edited for style and length.

Journal Reference:

Leilei Gu, Swapnadeep Poddar, Yuanjing Lin, Zhenghao Long, Daquan Zhang, Qianpeng Zhang, Lei Shu, Xiao Qiu, Matthew Kam, Ali Javey, Zhiyong Fan. A biomimetic eye with a hemispherical perovskite nanowire array retina. Nature, 2020; 581 (7808): 278 DOI: 10.1038/s41586-020-2285-x

<www.sciencedaily.com/releases/2020/06/200610102726.htm>


Optical Illusions

Optical Illusions can use color, light and patterns to create images that can be deceptive or misleading to our brains. The information gathered by the eye is processed by the brain, creating a perception that in reality, does not match the true image.

Here are a few of our favorites

The awkward dots

A simply brilliant image that plays real havoc with both your eyesight and your brain. This image was shared by Will Kerslake on Twitter with the caption “There are twelve black dots at the intersections in this image. Your brain won’t let you see them all at once.”

 

Confusing shadows

Another brilliant optical illusion created simply by the sun being at a specific place in the sky. This one seems to show oddities in the windows caused by their shadows which makes the building look like it belongs in Inception

 

The revolving snakes

This one is a simple trick of the eye. This is not an animated picture, it’s a static file that shows a mass of intertwined snakes. But if you stare at different sections you’ll see the snakes writhing and squirming

Source :

https://www.google.co.uk/amp/s/www.pocket-lint.com/apps/news/140473-best-internet-optical-illusions-you-won-t-believe-your-eyes.amphtml


Comparison of the Human Eye to a Camera

Comparison of the Human Eye to a Camera

The camera and the human eye have much more in common than just conceptual philosophy — the eye captures images similar to the way the camera does. The anatomy of the camera bears more similarities to a biological eyeball than many would imagine, including the lens-like cornea and the film-like retina. Similarities like these give the camera the appearance of a robotic eye. However, though there are many similarities between cameras and eyes, they are by no means identical.

Cornea and Lens

The cornea is the “cap” of the eye. This transparent (like clear jelly) structure sits to the front of the eye and has a spherical curvature. The lens of a camera is also transparent (glass) and sits at the front of the body. Like the cornea, the lens also maintains a spherical curvature. The corneal and lens curvature allows for the eye and camera to view, though not in focus, a limited area to both the right and the left. That is, without the curve, the eye and camera would see only what is directly in front of it.

Iris and Aperture

The aperture is to the camera as the iris is to the eye, and this reveals one of many similarities between cameras vs. eyes. The aperture size refers to how much light is let into the camera and will ultimately hit the sensor or film. As with the human eye, when the iris contracts itself, the pupil becomes smaller and the eye takes in less light. When the iris widens in darker situations, the pupil becomes larger, so it can take in more light. The same effect happens with the aperture; larger (lower) aperture values let in more light than a small (higher) aperture value. The lens opening is the pupil; the smaller the opening, the less light let in.

Focus in Eyes and Cameras

Both the eye and camera have the ability to focus on one single object and blur the rest, whether in the foreground (shallow depth of field) or off at a distance. Likewise, the eye can focus on a larger image, just as a camera (greater depth of field) can focus and capture a large scape.

Scope and Field of View

As the eye, the camera has a limited scope to take in what is around it. The curvature of the eye and the lens allow for both to take in what is not directly in front of it. However, the eye can only take in a fixed scope, while a camera’s scope can be changed by the focal length of different types of lenses.

Retina and Film

The retina sits at the back of the eye and collects the light reflected from the surrounding environment to form the image. The same task in the camera is performed either by film or sensors in digital cameras. This process underpins both how cameras work and how eyes work.

Source:

By Mallory Ferland

https://sciencing.com/comparison-human-eye-camera-6305474.html