This is a project to study the ways in which light directed at the retina aids or hinders the visualization of features in the eye. A narrow beam of light focussed on the retina is scattered back out of the eye from a) its focal spot at the retina, b) scatterers in the lens and vitreous and c) retinal or anterior structures which have been indirectly lit by light scattered out of the focal spot. The Scanning Laser Ophthalmoscope provides such ideally analysable light. Implementation of a technique of 'double scanning' used in underwater exploration will allow the separation of the three types of optical signal. In this study we will look at them individually: Type a) by itself provides a 'direct' image of the fundus, free of veiling from anterior scatterers and scatter within the retina. Type b) provides information on the anterior scatterers themselves - what they are and how they are organized. Type c) represents an indirectly illuminated image of the fundus. This complete picture is like a mosaic of all the views seen at the edges of the illuminated area in slit lamp and ophthalmoscopic observation.