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>


Covid19 safety measures in practice update

As the COVID 19 regulations have now eased, we are able to offer routine examinations in addition to examinations for those who may have specific concerns about their vision.

Please contact the practice on 020 72220066 or email info@uniaopticians.co.uk to book an appointment.

We are currently available on Monday, Wednesday and Thursday, from 10.00am to 3.30pm, but please check our website & contact us as these are due to change to allow for more appointments.

We are operating a closed door system, so we can control the number of customers in the practice at any time. All staff are wearing full PPE, and we would request all customers entering the practice to wear a face covering. (This can be provided if patients do not already have one) There are hand sanitiser stations both at the door and throughout the store.

We are able to dispense spectacle frames from our complete range, for prescriptions to be made up, and are sanitising any frames that are tried on after each customer. All equipment & surfaces are also sanitised after each customer visit.

In order to limit face to face contact we are able to carry out OCT scanning & retinal imaging. This enables us to have a fully detailed view of the retina and to detect the potential for many ocular diseases.

We look forward to seeing you soon.

The Unia Team.

 


Covid19 safety measures in practice

As guidelines continually change, we are now open for emergency and essential eyecare.
This means that if you have any concerns about your vision or you are feeling anxious about your
eyes, we are now able to see you, on an appointment only basis.

This also includes circumstances where you would like to update your prescription where a change
has occurred, if you require a spare pair of glasses, repairs, wish to purchase sunglasses or where
your contact lens supply is due.

However, it is still necessary for you to call or email the practice first so that we can best manage
appointments to minimize face to face contact.

Where a prescription is out of date, in the absence of any problems, a telephone consultation/video
call can be arranged to verify that all is well before the glasses are dispensed.
All routine eye examinations remain suspended in the UK.

In order to maintain social distancing within the practice, we are operating a closed-door policy.
We would like to reassure you that we are following strict hygiene and sanitizing practices within the
consulting room and throughout the store so that everyone remains safe and all staff will be wearing
the necessary PPE.

Currently, the frames may not be directly accessible to touch on the shelves, however they can still
be viewed and tried on, as many as desired. All frames that have been handled, will be thoroughly
sanitized to ensure safety for successive patients. Wherever possible, when ready, spectacles will be
posted to patent’s homes to avoid unnecessary travel/risk.

Contact lens patients will be able to reorder a routine supply of contact lenses and in most cases,
these can be delivered directly to homes. Where a contact lens after care is due, in the absence
of any problems, a telephone/video call can be arranged to verify that all is well before the lenses
are ordered. Patients will then be asked to return for a full after care appointment once guidelines
change/as necessary.

Contact lens solutions, eye drops, supplements and other accessories will still be available.
Again, these can be posted out to patient homes to prevent unnecessary travel to the practice.
If you are feeling unwell or have been in contact with someone with Covid 19 we advise you not
to attend the practice until it is safe to do so. If any patient is unsure of their symptoms, they are
advised to call NHS 111 for advice.

We look forward to welcoming you back soon, albeit to a new ‘normal’

Best wishes

The Unia Team

 


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


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.