| 摘要 |
A lens allows a wide field of view of the interior of a patient's eye to be observed without requiring the eye to be dilated. The lens is nonsymmetric and formed of an optically transparent material having two nonspherical surfaces. The surface of the lens facing the patient's eye has a curvature sufficient to bend the image forming rays emanating from the undilated eye towards a second surface which has a curvature sufficient to form the rays into a planar, real, inverted image of the fundus with a field of view of greater than 60 DEG and a ratio of the effective focal length of the lens to the lens diameter that is less than 0.5.
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