Abstract
Purpose :
It is difficult to attribute parasitic effects in the human vision to its specific origin. Starburst for example, a radially oriented ray pattern around bright light sources, may have physical reasons due to scattering or diffraction processes in the eye or it may be caused by neuronal effects. Access to the image projected on the retina helps to understand such vision effects. In combination with virtual intraocular lens implantation (VirtIOL), the image on the retina provides information regarding the optical elements of the eye including the IOL characteristic. We present a method to photograph the image projected on the retina.
Methods :
Usually emitted or reflected light from an object is focused on the retina, where a very small amount of light is backscattered. A beam splitter, positioned in front of a subject’s eye, allows to focus this light onto a camera sensor. Following tasks have to be accomplished: (1) the selection of a camera system with an high quantum efficiency (Andor 940 BV - quantum efficiency 95%), (2) optimized stray light management to eliminate background illumination, (3) identify a device mimicking the effect of an implanted IOL placed just in front of the beam splitter. This setup (see fig. 1) enables to study the IOL design specific influences on vision and even to investigate possible differences between the retinal image and the subject’s perception.
Results :
We successfully established a setup to photograph the image formed on the retina. The integration time is still in the order of 200 s and therefore a cooled camera system for thermal noise suppression is essential. Exemplifying this approach fig. 2 shows the retinal image of a subject looking at a monitor in 6 m distance showing the letters “ARVO” (18.5 cm horizontal width on the monitor). The image was taken with a monofocal IOL virtually implanted.
Conclusions :
We developed a method to photograph the image projected on the retina of a subject. In combination with a virtual IOL implantation this setup provides access to the influence of the optical IOL characteristics on the retinal image comparing to the individual image perception. This helps to understand and characterize imaging phenomena such as glare and starburst.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.