Fig. 7. At the very bottom of sleeve adjustment, a bright, thin, focused image will emerge on the retina if the far point of the eye is 40 cm in front of cornea or about 35 cm behind the retinoscope. Raising the sleeve from the bottom moves the virtual focus of the retinoscope closer to the horizon, allowing the detection of lesser amounts of myopia until the middle the retinoscope, where plano is detected. The distance that the sleeve is adjusted is a measure of the refractive distance between plano and -2.25 D. |