Abstract
By using steer's eyes, which are similar in optical characteristics to human eyes, we have measured the stray light in them. (See Table 1). The results are summarized as follows : 1. The effect of time lapse after the excising of steer's eyeballs is negligible at least up to 10 hours. (See Figs.2〜4) 2. The quantity of stray lights increases as the light source approaches a point on the visual line, especially when the light source is within 10°from the visual point. (See Fig.5) 3. The causes of stray light are : (1) optical defects of eyes when the light source is within 10°of the visual point; (2) diffusion of light on the surface of the cornea at angles greater than 10°. 4. The smaller the iris aperture, the smaller the quantity of stray lights. (See Figs. 6 and 9) 5. When a large light source is divided into 1°units, the total sum of the stray light from each unit is almost equal to the quantity of the original light source. (See Table 4) 6. In order to obtain the ratio of E_θ/E_0, the following equations are used : θ>1° E_θ/E_0=exp{(-lnθ)^3-0.25}+0.032θ^<-1.8> θ≦1°E_θ/E_0=exp(-0.17θ) where, E_0 : Illuminance of fovea when the light source is on the visual line (θ=0°) E_θ : Illuminance of fovea when the light source deviates θ°from the visual line.
