Your eyeballs and an LCD
Being graced with perfect vision, I have never personally experienced any of visual problems commonly associated with long-term computer use. Most frequently reported is the non-threatening but irritating monitor eyestrain and irritation. Also of importance, however, are problems with the technology itself—especially for those that have poor eyesight or, in some cases, no eyesight to begin with. Thankfully, most of these situations can be solved quickly and effectively.
First and foremost, let's tackle general eyestrain. Visual problems such as this are one of the most frequently reported problems associated with computer use. In recent years, businesses have shifted more and more of their work to digital format, causing the general population to spend hours, even entire days, working exclusively through their computer terminal. In some cases, eyesore and irritation can occur after only just thirty minutes of use, however a more common timeframe falls between one and two hours of continued use.
Symptoms resulting from extended periods of computer use include soreness, irritation (including itchiness and watering), headaches, excessive blinking or squinting, focusing problems and blurred vision. The most common cause of these problems can be found in your environment—poor lighting, glare from the screen or nearby windows, poor screen positioning or problems with the contents of the screen (font size, for example).
To be sure you don't fall into one of these categories, always make sure that you have plenty of light available in the room and that no sources of light cause glare in your immediate surroundings. (We'll talk more about screen problems such as small font sizes.) For others, the problem is due primarily to eye fatigue—in this case, practice vision breaks (even as simple as looking across the room, adjusting your focus depth or holding your eyes closed for several seconds) every hour or so of computer use.
For technology-based solutions, check the refresh rate and font-smoothing on your monitor. Except for LCD monitors, changing the refresh rate—the rate at which the picture on your screen is continually redrawn—can help reduce eyestrain. For Windows users, this option can be found under Control Panel, Display, Settings, Advanced. Mac users can find the same setting under Apple, System Preferences, Displays. Generally a higher refresh rate (between 72 and 75) will be easier on your eyes, although some find that a lower or middle (personally I prefer 65, but I have odd preferences) rate is more comfortable.
In addition, both PC and Apple machines have the capability to smooth the edges of most fonts, which increases the general aesthetics and reduces the workload on your eyes. For Windows, this setting is found under Control Panel, Display, Appearance, Effects and enabling ClearType. Apple users will be pleased to hear that font smoothing comes enabled by default, although you can tweak the settings if you desire.
While it would be nice to think that all vision problems are the result of our surroundings, occasionally the problems are due to your vision itself. Especially if you wear prescription glasses or contacts, you may want to consult your eye doctor for further assistance. (Yes, I know this isn't very helpful, but that's why the pay the doctors and not me.) Even if you do not wear glasses regularly, however, you may require special assistance when dealing with computers or other screen-based technology.
The issue of vision and computers is not limited merely to discomfort, however, as some situations are of a more practical or limiting nature. For some, the contents on the computer screen itself are simply too small to focus on. In this case, look at the display properties of your computer to change the universal size of fonts. This will eliminate the need to set font sizes to 16-points in email and word processing programs, as well as allow you to better read the contents of most programs and websites.
Finally we come to the issues for visually impaired persons. In this case, you are most likely already aware of the options available to you. Software-based programs such as screen-readers will turn the daunting or impossible dilemma of reading your screen into an audible task. There are also hardware options available that can convert a traditional keyboard into a brail reader and transcriber. For more information about these solutions, we'll all be better served by either contacting somebody more resourceful than myself, or contacting me so I can put you in touch with said person.
Regardless of your situation—eyestrain, screen problems or visual difficulty that goes deeper than inconvenience, hopefully the above solutions and suggestions will help bridge the gap between your daily duties and the difficult world of technology.