Fred’s Head from APH, a Blindness Blog

Fred’s Head, offered by the American Printing House for the Blind, contains tips, techniques, tutorials, in-depth articles, and resources for and by blind or visually impaired people. Our blog is named after the legendary Fred Gissoni, renowned for answering a seemingly infinite variety of questions on every aspect of blindness.

(See the end of this page for subscribing via email, RSS, browsing articles by subject, blog archive, APH resources, writing for Fred's Head, and disclaimers.)


Tuesday, June 01, 2010

What is Computer Vision Syndrome?

Computer Vision Syndrome (CVS) is a very real eye problem that affects many people who spend long hours at the computer screen. It is no less an example of repetitive strain injury (RSI) than the strain on the wrist which is often brought on by excessive keyboard activity.

In Computer Vision Syndrome the work environment itself can contribute significantly to the problem. Inadequate lighting, harsh fluorescent lighting, glare from windows and sitting too close or too far away from the computer monitor can all exacerbate the condition. The color of the text background and the way in which the contents are displayed on the screen can also be contributary factors.

There is a fundamental difference between reading text in print and text on a computer monitor. When reading text on printed material the eye easily focuses on the letters as they are straight lines. On a computer screen this is not the case as the letters comprise a number of pixels or tiny dots which require the eye to constantly refocus. This creates fatigue and eyestrain.

Symptoms of Computer Vision Syndrome

A syndrome can be described as a concurrent set of symptoms associated with a medical condition. While the most commonly experienced symptom is eyestrain causing eyes to feel tired, other parts of the body are affected as well. Headaches, backache and neck ache often accompany eyestrain as do blurred vision, double vision and/or distorted color vision.

Slowness in changing focus is another symptom. A slight delay begins to develop in the eye's ability to bring the newer image into focus when quickly changing from looking at something in the distance to looking at something close to (or vice versa). Overuse of the focusing muscles tires the eyes and a dry or burning sensation often accompanies eyestrain.

Everyone's at risk of developing Computer Vision Syndrome if he or she, young or old, spends long periods of time working at a computer. The key to prevention or minimization of the problem is to take regular breaks from the monitor and walk about periodically.

When visiting the eye doctor make sure you communicate the fact that your daily routine involves at least 2 hours' work on a computer. The good news is that, in the vast majority of cases, computer eyeglasses can be prescribed which will entirely eliminate the symptoms. These generally require a different prescription from regular eyeglasses. Features incorporated into computer eyeglasses may include a computer tint, UV tint, anti-reflective coating and even a prism. Remember, though, prevention is better than cure and incorporate one very important feature into your work environment - take a break!

For more information on vision, click this link to visit


EyeDefender is a software package that will nudge you, in various ways, every hour or so to give your eyes a break. After you install EyeDefender, you'll be able to set up how often you want to rest and for how long. I chose 2 minutes every 60 minutes. You can choose different images to look at for your break period and you can always stop your break by hitting the Esc key.

If you don't want to install EyeDefender, setting a simple reminder for yourself to take a break every hour, and blinking frequently for about 2 or 3 minutes should also help alleviate symptoms.

To see what EyeDefender will look like after you install it, watch this screencast from
Click this link to download EyeDefender:

No comments:

Subscribe to receive posts via email

* indicates required

Browse Articles by Subject

Follow us on Twitter


Write for us

Your input and support in the evolution of Fred's Head are invaluable! Contact us about contributing original writing or for suggestions for updating existing articles. Email us at


The American Printing House for the Blind (APH) makes every attempt to ensure the accuracy and reliability of the data contained in the Fred's Head articles; however, APH makes no warranty, guarantee, or promise, expressed or implied, concerning the content or accuracy of the information provided in Fred's Head. APH does not endorse any technique, product, device, service, organization, or other information presented in Fred's Head, other than products and services directly offered by APH.

The products produced by the American Printing House for the Blind are instructional/teaching materials and are intended to be used by trained professionals, parents, and other adults with children who are blind and visually impaired. These materials are not intended as toys for use by children in unstructured play or in an unsupervised environment.

The information and techniques contained in Fred's Head are provided without legal consideration (free-of-charge) and are not warranted by APH to be safe or effective. All users of this service assume the risk of any injury or damage that may result from the use of the information provided.

Information in Fred's Head is not intended as a substitute for professional advice or treatment. Consult your physician before utilizing information regarding your health that may be presented on this site. Consult other professionals as appropriate for legal, financial, and related advice.

Fred's Head articles may contain links to other websites. APH is not responsible for the content of these sites.

Fred's Head articles created by APH staff are (C) copyright American Printing House for the Blind, Inc. You must request permission from APH to reprint these articles. Email to request permission.

Any submissions to Fred's Head should be free of copyright restrictions and should be the intellectual property of the submitter. By submitting information to Fred's Head, you are granting APH permission to publish this information.

Fair Use Notice: This website may contain copyrighted material whose use has not been specifically authorized by the copyright holder(s). This site is operated on the assumption that using this information constitutes 'fair use' of said copyrighted material as provided for in Section 107 of U.S. Copyright Law.

Opinions appearing in Fred's Head records are solely those of the contributor and do not necessarily reflect the views of the American Printing House for the Blind.