CVS
CVS stands for Computer Vision Syndrome. This is a disorder that is caused by staring at a computer display or VDT (Video Display Terminal). This page will focus on the effect of CVS on eBook Readers.
[edit] American Optometric Association
This is an organization devoted to Optometry and associated vision issues. They have created several pages to explain CVS. These include:
http://www.aoa.org/x5253.xml Causes at work. Has links to:
- What causes Computer Vision Syndrome?
- How is Computer Vision Syndrome diagnosed?
- How is Computer Vision Syndrome treated?
http://www.aoa.org/x5374.xml Occupational Issues. Has links to:
- Computer Vision Syndrome Symptoms
- The Relationship of Computer Vision Syndrome to Musculoskeletal Disorders
- Impact of Computer Use on Children's Vision
- The Effects of Video Display Terminal Use on Eye Health and Vision
- Criteria for Determining Whether the Need for Eyeglasses or Other Treatment is Related to Computer Use.
[edit] Display Factors
Settings can be adjusted to combat contrast and glare issues, color choices can be adjusted. However some things are inherent in the display itself.
- a CRT generally has a thick glass in front, which forces the eye to refocus from the front to the back of the glass constantly, contributing to eyestrain.
- LCD monitors have less of a boundary between LCD pixels and the front of the screen, causing the eye to work less to focus.
- Both CRTs and LCDs have screen refresh - The can be a flickering effect that places undue strain on the eyes, causing fatigue. This can be exacerbated by florescent lights being used in a room where the display is being used.
- E-Ink generally is reported to have the least eye strain. Some attribute this to lack of refresh and others to lack of backlight.
[edit] Anecdotal Evidence
While scientific study does not prove many of the claims of users there are enough claims to provide a few tips to minimize the problems that some people experience.
- Decrease the backlight level to the minimum acceptable (This will also increase battery life on portable devices).
- Increase the Font size to reduce eye strain.
- Change the color choices to something that is pleasant to view. Experimentation is required.
