Tag Info

New answers tagged

13

Short answer Spectral sensitivity of cats indeed ventures into the UV, but not beyond ~320 nm. Their maximum is likely similar to ours, i.e., ~750 nm. Background The spectral sensitivity of blue cones (photoreceptors detecting low wavelengths) of many species, including humans and cats, extends into the UV range (Fig. 1). Fig. 1. Human cone absorption ...


1

Your eyes can dilate behind sunglasses, especially when the main source of light (the sun) is blocked, and ambient light decreases. Regular sunglasses offer some protection against certain UV wavelengths, but not enough to protect your eyes when looking directly at the sun (or, during an eclipse, the corona). Most sunglasses are mainly designed to, first and ...


3

Behar-Cohen et al. notes the periphery of the cornea has a focusing effect: UVR incident from the periphery is refracted into the eye, and due to the focusing effect of the cornea, UV radiation is on average 22-fold stronger at the nasal limbus, which is the typical site for pterygium and pinguecula. Moreover, UV radiation is on average eight times ...


-1

I see one possible advantage to round pupils. A slit pupil gives higher visual acuity vertically than horizontally because of diffraction and when a slit pupil is very nearly shut, there's high diffraction in the horizontal direction giving poor horizontal visual acuity. A round pupil on the other hand gives a creature the highest visual acuity in all ...


2

Its down to the structure of your eyes. The eyes are made of rods and cones, which have difefrences in detecting light. Now, compare the images below. As you can probably see, the peripherl vision is predominatlty due to your rods, and your central vision made of cones. Measured density curves for the rods and cones on the retina show an enormous ...


0

Because peripheral vision uses the peripheral retina,which has mostly rods as photoreceptor,while central vision uses the foveola,a central part of the retina which mostly has cones as photoreceptors. Rods are more sensitive to light. That is why they are more efficient in the dark.



Top 50 recent answers are included