Purpose: To analyze straylight resulting from different sources (cornea, lens, wall translucency, and fundus reflectance) in combination with different properties (age and pigmentation). To give formulas for straylight calculations.
Methods: In straylight on the retina multiple scattering can be assumed to be unimportant. Consequently, an additive model can be applied.
Results: An efficient parameter to quantify straylight is the "straylight parameter" s(theta), with theta the scatter angle. The model reads s(theta) = s(cornea)(theta) + s(lens)(theta) + s(wall)(theta) + sfundus(theta), and each of these sources is analyzed as sx(theta) = sx,base(theta) + a(age)*sx,age(theta) + p(pigm.)*sx,pigm.(theta).
Conclusions: The most important effects, viz., s(lens,age), s(wall + fundus,pigm.) and s(cornea + lens + fundus,base) as well as a(age) and p(pigm.) were estimated. With the straylight parameter different effects of straylight, notably its disabling effect of contrast reduction, follow directly.