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>


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


Practice reopening 1st of June

We are pleased to inform you that we will be reopening the practice on the 1st of June 2020, by appointment only. For the foreseeable future, we will be operating a closed door policy to maintain social distancing. This is in line with current government and regulatory guidelines which we continue to monitor closely.

Our temporary opening hours will be Monday, Wednesday and Thursday 10am to 3.30pm. Please call or email in advance before attending.

As we prepare to reopen, the health and well-being of our patients and staff remains our priority. Strict hygiene measures, social distancing and use of appropriate PPE will continue to be in place to ensure everyone’s safety.

If you have any queries, please email us at info@uniaopticians.co.uk. Please check our ‘News’ page for full details and further updates.

As always, we remain committed to providing our patients with excellent customer care and service and look forward to welcoming you back very soon.

 

 


National Eye Health Week Day 2

We have a selection of information leaflets available to pick up in store, regarding all elements of eye health,

includingcomputer screen use, eating well for eye health and looking after children’s eyes.


National Eye Health Week

This week is National Eye Health Week.

We are raising awareness of the benefits of regular eye examinations.

Please copy and paste the link below to take part in the survey

http://www.visionmatters.org.uk/eye-health-questionnaire/eye-health-questionnaire

There are a million people in the UK currently living with ‘avoidable’ sight loss – leaving them unable to do things such as drive. Forecasters predict this figure could rise by a third by 2030, if action isn’t taken now[1].

Prevention and early diagnosis of common eye conditions are key to reducing the number of people suffering sight loss unnecessarily” explains David Cartwright Chairman of Eye Health UK “however, in towns and cities like Bristol, Liverpool, Luton and Manchester we are seeing a worrying number of people failing to take up their entitlement to free NHS sight tests and displaying high levels of smoking and obesity – two lifestyle factors linked to sight loss.”

Lifestyle habits impact your eye health regardless of your genetic predisposition.[2] Being physically active has been shown to reduce your risk of visual impairment by 58 per cent versus somebody with a sedentary lifestyle[3]; whilst a Body Mass Index (BMI) of 30+ has been linked to the four most common causes of sight loss: macular disease, glaucoma, cataract and diabetic retinopathy.[4]

Research published in the British Medical Journal reveals as many as one in five cases of Age-related Macular Degeneration (AMD), the UK’s leading cause of blindness, are caused by tobacco consumption.[5] Making smoking directly responsible for around 120,000 cases of AMD in Britain today.[6]

Poor uptake of regular eye tests is another big risk to the nation’s eye health. Almost 14 million (13.8) of us fail to have our eyes checked once every two years, as recommended, and one in 10 of us have never had our eyes checked.[7]

Go to visionmatters.org for more information.


National Sunglasses Day – Wednesday 27th June

Protect your eyes from harmful UV light with sunglasses. Ensure full UV protection with good  quality lenses.

Maui Jim sunglasses offer the greatest level of protection, and are recommended by the Skin Cancer Foundation.

Available in ready to wear and prescription. See in store for details.


Top tips from National Eye Health Week

After the recent National Eye Health Week, we could all take something from these top tips.

If you are concerned about anything eye related, you should seek the advise of your Optometrist.