Study of filtered light on potential retinal photic hazards with operation microscopes used for ocular surgery.

There have been numerous reports of retinal photic injury from operation microscopes used during cataract surgery. The risk of injury has been associated with the intensity of the light directed into the eye, short-wavelength emission, user technique, exposure time, and direct axial lighting. We evaluated use of light transmission filters to modify a tungsten-halogen light source spectrum to reduce the risk of retinal photic injury. A two-light source filter combination was found with a color profile acceptable for intraocular surgery that reduces the risk of retinal photic injury by a factor of approximately 2.5.