Recently a new method of retinal imaging by laser scanning ophthalmoscopy was developed that overcomes the intensity problem of conventional fundus photography and promises further advantages. The laser scanning ophthal-moscope has been modified by incorporating an adaptive optical feedback system for laser beam control. For wave-front reconstruction maximum likelihood methods and the Gerchberg-Saxton-algorithm are applied. The system essentially provides an elimination of optical eye aberrations which diminish the fundus image quality. On the other hand by active focus control and/or wavefront sensing the aberrations of the human eye like astigmatism of the cornea and spherical aberration of the lens can be measured.
"Active Optical Focusing Of The Laser Scanner Ophthalmoscope", Proc. SPIE 0498, Laser Scanning and Recording, (27 November 1984); doi: 10.1117/12.944523; https://doi.org/10.1117/12.944523