| 摘要 |
<p>A lens (1) allows a wide field of view of the interior of a patient's eye (2) to be observed without requiring the eye (2) to be dilated. The lens (2) is nonsymmetrical and formed on an optically transparent material having two nonspherical surfaces (3, 4). The surface (3) of the lens (1) facing the patient's eye (2) has a curvature sufficient to bend the image forming rays (8, 10) emanating from the undilated eye (2) towards a second surface (4) which has a curvature sufficient to form the rays (8, 10) into a planar, real, inverted image (7) of the fundus (6) with a field of view of greater than 60° and a ratio of the effective focal length of the lens (1) to the lens (1) diameter that is less than 0.5.</p> |
