Illuminated PHOROPTOR Refracting Instrument Overview You work hard to help improve your patient's eye sight, but who is looking out for yours? No more straining to read the dials in a dark room. With lighted sphere, cylinder power, and the cylinder axis scales, you can put the pen light down and leave the lights off through the entire refraction. Illumination is provided by cool-running, energy efficient LEDs (Light Emitting Diodes) that light only what you need to see without affecting the darkened refracting environment. The best of all they are maintenance free so you'll never need to change a light bulb. Every Phoroptor comes with a limited lifetime warranty, the best in the industry