Stars & eyes?

Question

I asked the Q: 'why do you see stars better from the corner of your eye than if you look at it directly?' -- is it to do with the blind spot

i now know that it is definitely the fovea (area in the retina with the most light- sensitive cells) that creates this - but how/why? (details?)

Answer 1

I'm pretty sure the peripheral vision can show movement, colors, and light better than the center of your eye. So that's why because stars are light in the sky.

Answer 2

It doesn't really have anything to do with the blind spot (the blind spot is cancelled out by your brain when you use both eyes anyways).

It's because the fovea has a very high density of light sensitive cells and produces the sharpest images with clearest color distinction that we tend to look at things directly when observing them. The high resolution is due to the high density of cones (color-sensing cells) and the fact that each cone is connected to a single neuron. Cones require a fairly high level of light to function, however, and are of little use in the dark.

The outer areas of the retina, on the other hand, have a higher percentage of rods (black and white photoreceptors). Unlike cones, however, several rods are wired into one neuron. This means that the image generated is much more indistinct, but the rods are much more sensitive (and more useful in low-light situations).

When you look off-center at an object, you focus the light on the outer areas of the retina, where rod density is highest. When you look at an object in the dark, you'll notice that colors are indistinct, and everything looks fuzzy. You'll also notice that it is much easier to see things on the periphery of your vision (probably an evolutionary advantage to help spot predators at night). When you look at a star, you tend not to notice the lack of color (since they are effectively white) and the fuzziness (there isn't much detail to see).

Answer 3

Be a little patient with your answerers, it took them a little while to complete their answers and you can find the complete answers here at your previous question:

http://answers.yahoo.com/question/index;_ylt=Alik1kudhDbGeIesJKvUQFP9xQt.;_ylv=3?qid=20071002114317AAVviJe

Also, the rods are in the periphery (not in the fovea) and rods are more sensitive in the dark and see black and white (not color, the cones are for color). Here is a picture:

http://www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_9/ch9p1.html