眼底計測とdistortion

Distortion of the Photographed Image in Measurements of the Ocular Fundus

I．緒言

　平凸レンズを虫眼鏡のようにして碁盤目をみると直線が歪んでみえる。レンズの中心から縁にいくにしたがつて歪みは強くなる。

　これを像の歪曲distortionといい，球面収差，コマ非点収差，像の湾曲とともにレンズの収差の一つにあげられる。

Distortions of the eye and the fundus camera as a combined optical system were computed to see the influence on the measurement of the fundus through analysis of fundus photographs.

1. Distortion of the Gullstrand's schematic eye was calculated and the obtained results were as follows : When the external angle of the light projected into the eye was 5°, the distortion at the Gaussian image plane was-0.095% ; when 10°, -0.383% ; 15°, -0.872% and 20°, -1.574 %.

2. Distortion in case of the optical system composed of the schematic eye and the Olympus fundus camera GRC was shown to be as follows :