According to this web page for writers publishing their work, Times New Roman, a member of the Serif font family, "has hooks or wings at the tips of the letters. They act as a guide to move your eyes from one letter to the next. This reduces eye strain and makes your book more readable" (from http://www.artbookbindery.com/Autobiography.htm). But generally it seems that the best way to avoid eye strain is to increase the font size of whatever font you use: "Avoid fonts that are smaller than 10 points or larger than 12 points (except in headlines or to embed details). For many readers, small type makes reading difficult. On the other hand, over-large type increases the reader's need to scroll in order to read long [documents] and can make your [document] look less professional. ." (from http://office.microsoft.com/en-us/FX011456181033.aspx) "When we stare at the monitor we blink less frequently, which dries the eyes; using an over-the-counter eye lubricant can help moisten them. Squinting at blurred, fuzzy or tiny characters for hours can contribute to CVS. "If you have to lean forward or backward to read what's on the screen, the text is too small," says Dr. Gaudet. "Increase the point size until you can read it easily while sitting back comfortably in your chair." To increase a font's point size in a word-processing program such as Word, go to Format > Font > Size. To increase point size while reading on the web, in Internet Explorer go to View > Text Size and select from Largest to Smallest. Reduce lighting and glare Check your workspace for sources of glare. The monitor acts as a mirror, reflecting shiny walls and light sources. Reposition it or use curtains, blinds or a special anti-glare screens to eliminate distracting reflections. To reduce glare, adjust the brightness and contrast display settings on your computer's monitor to suit your workstation's lighting. To do this, go to Start > Control Panel > Display > Settings > Screen Resolution. Slide the arrow to the desired setting. According to the Canadian Centre for Occupational Health and Safety, the computer monitor is a source of light itself, so it doesn't require additional illumination. Use a floor or desk lamp to throw a spotlight on papers. Ask if you need computer glasses Special computer glasses, which are usually prescribed by your optometrist, cost from $145 to $200 and help your eyes focus on the screen. While they can help grown-ups, children generally don't need them. "Kids' focusing power is so strong that they don't have the same vision problems that adults do in this situation," explains Dr. Gaudet. If your son or daughter complains about sore eyes, an optometrist-recommended eye lubricant should offer relief. "The best treatment for kids is prevention," she says. "Limit your children's time on the computer so they don't end up with eye strain." If you wear contact lenses, remove them and don your glasses during computer time. "Contact lenses exacerbate the symptoms of CVS because you don't blink enough to keep the eyes moist," says Dr. Gaudet. "You'll be more comfortable with your glasses on at the computer." Finally, if you can afford to buy a flat-screen computer monitor, your eyes will thank you. "The higher-imaging quality of these screens [is] much easier on the eyes," says Dr. Gaudet. "The images have sharper edges, which contribute to the overall clarity of what you're looking at onscreen, which in turn contributes to eye comfort." (from http://www.microsoft.com/canada/home/healthandwellness/2.2.12_stopsquintingcombatcomputereyestrain.asp)

Ariel is the easiest font to read both o and off the computer its easy on the eyes and helps people who suffer from dyslexia see the words more easily. hope thi has helped answer your question

Actually, what really irks me is light print on a dark background regardless of the font. It's much easier to read dark on light.