Has the compound contact lens element the inverted image ophthalmoscope contact lens device

摘要

An indirect ophthalmoscopy contact lens device includes a contact lens having a first posterior lens surface with a concave shape substantially corresponding to the shape of an average cornea and an image forming lens for collecting and focussing light exiting the patient's eye and entering the contact lens when in place on the patient's eye for forming an aerial image of the fundus of the patient's eye. The contact lens comprises a compound contact lens element including a posterior lens portion cemented to an anterior lens portion. The posterior lens portion includes the first posterior lens surface and a first anterior lens surface, and is made of a material having a first index of refraction and a first Abbe value. The anterior lens portion has a second posterior lens surface with a shape substantially matching a shape of the first anterior lens surface and a second anterior lens surface having a convex shape. The anterior lens portion is made of a material having a second index of refraction and a second Abbe value. At least one of the second index of refraction and the second Abbe value is different from the first index of refraction and the first Abbe value, respectively. The optical cement preferably has an index of refraction corresponding to the first or second index of refraction.