"The question you answered regarding dentists' lights has prompted me to ask whether the extremely bright lights used by opticians can damage the eye. Two years ago, I had an eye check-up. During a prolonged use of the examination light by the optician, my right eye became painful. Immediately after, a test revealed that I could not see clearly at the centre of my vision – hardly surprising as I could still see the after-images. Ever since that examination, I have been seeing something like that after-image in the middle of my eye when light levels are low, and I can no longer see the colour green in that area. I was examined at an eye hospital, but no signs of age-related macular degeneration were found. The specialist said my eye could not have been damaged by the optician's light. However, I am nervous about having my eyes tested again."
Dr Fred Kavalier answers your health question:
Certain types of bright lights can damage the eyes. The light that is emitted by welding arcs, for example, emits enough ultraviolet radiation to damage the cornea. This condition is almost always temporary. Intense visible lights can dazzle, but they should not damage the eye unless they contain ultraviolet radiation, so the examination lights used by opticians should not cause permanent damage. It is more likely that there was an underlying weakness which only became apparent after the exam. It is important to have regular check-ups, but you should make the optician aware of what happened last time.
Please send your questions and suggestions to A Question of Health, The Independent, Independent House, 191 Marsh Wall, London E14 9RS; fax 020-7005 2182; or email email@example.com. Dr Kavalier regrets that he is unable to respond personally to questions.