Proximity-sensor dimmer device as an aid in the reduction of operating microscope-induced retinal phototoxicity

The length of exposure to the light source of the operating microscope is a major factor determining retinal phototoxicity. In our experience, for about 20% of the time during cataract surgery, the surgeon is not looking through the oculars. To take advantage of these times, we designed a device, a proximity switch consisting of an infrared sensor mounted between the oculars in the operating microscope. When the surgeon's forehead approaches the microscope to look through the oculars, the sensor increases the illumination; when the surgeon moves away, it is automatically reduced. The resulting decreased overall exposure to light may reduce retinal phototoxicity.