US Patent 7422327 Retinal topography diffractive fundus lens

Embodiments of the present invention provide a fundus lens. This fundus lens includes a first aspheric lens and a second aspheric lens and a diffractive optical element. This diffractive optical element is placed between the first and second aspheric lens and illuminated by an off access light source. The diffractive optical element contains a predetermined pattern which may be directed and imaged on a fundus. The first and second aspheric lenses are operable to gather light scattered by the fundus and provide the gathered light to a fundus camera. This fundus camera may then be operable to process the gathered light and determine the topography of the fundus.