Dear Dr. SerVaas: My daughter uses a computer many hours a day and I noticed there is a blue light on the power button. There is also a blue light on her monitor. Could you tell me if this is dangerous? We have macular degeneration problems in our family. Could this increase her chances of getting cataracts and macular degeneration? I've read that blue light should be blocked.
Margaret Riley
Ottumwa, Iowa
Dear Reader: With the assistance of the American Academy of Ophthalmology, we received the following information regarding sources of blue light and possible exposure from computers, televisions, etc.
Stanford retina specialist Mike Marmor, M.D., explained: "TVs and computers are not harmful in terms of light or UV. Blue blocker glasses are basically for outdoors and are just a refinement of UV blocking glasses or sunglasses. They are in some way sunglasses, because if blue is blocked, the glasses must have a yellow or orange cast."
Seattle-based ophthalmologist Richard Bensinger, M.D., adds: "As a matter of simplicity, blue is used as a generic term for that end of the spectrum containing higher energy waves. This is perceived as blue, violet, or beyond (ultraviolet). It is these waves that have been speculated as causing damage to tissue and, indeed, are the probable cause of sun damage, sunburn, and perhaps cataracts and macular changes. So a 'blue blocker' as a lens or a cream is anything attenuating that portion of the spectrum. Sunlight is by far the most intense natural source and it is, of course, more intense at higher altitudes. Indoor lighting rarely has enough density to cause any problem at all. For instance, the difference between bright outdoor sun and standard indoor illumination is about 100,000 to one. So indoor stuff is hardly a problem. Only in settings such as indoor tanning machines and certain types of lasers is artificial light a problem."
Researchers suspect that there are several causes of cataract, including smoking, sun exposure, and aging. Smoking may also increase the risk of age-related macular degeneration, a leading cause of blindness. See page 34 for more on macular degeneration.
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