Stenopaeic slit
Device used in optometry
From Wikipedia, the free encyclopedia
The stenopaeic slit is a black disk with a thin slit through it used by optometrists in detecting the level of an astigmatism.[1]
The disk is rotated so that the slit is oriented at different angles, changing the retinal blur size. The stenopaeic slit is more useful to screen for a high degree of astigmatism in patients who have poor vision.
