Based on the evidence that cataracts degrade image resolution, primarily by light scattering, an attempt was made to see through a cataract by optically compensating for the scattering. The technique employed is known as phase aberration balancing by use of holography. Using such a holographic filter, resolution through an in vitro human cataract was improved from 20/200 to better than 20/15.
Miller D, Zuckerman JL, Reynolds GO. Holographic Filter to Negate the Effect of Cataract. Arch Ophthalmol. 1973;90(4):323-326. doi:10.1001/archopht.1973.01000050325018