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pecularities of eyes?
The eye is, just as the telescope objective, subjected to the effects of diffraction of light and wavefront aberrations. Physical and optical properties of human eye vary individually, often significantly; those presented here are based on experimentally determined averages Eye photoreceptors cells, cones and rods, form the light-sensing lining of the retina. We need them to sense light, just as we need nerve endings in the skin to sense touch. They range in size from ~2? to over 10?, in general becoming larger toward the outer area of the retina, the cones more so than the rods. Dominant retinal photoreceptors at medium-to-small pupil sizes (daylight and indoor light conditions) are the cones, while at large pupil sizes (in low-light conditions) the dominant photoreceptors are the rods. The two differ significantly in, among other properties, their respective resolution limits.The area of highest cone acuity coincides with the area of their highest density and smallest individual size - foveola. Area of the highest rode acuity is just outside the macula, in the ring roughly centered at the fovea, some 10° to 15° in radius.


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