What are the physical differences of the eyeball that makes people see differently?

Question

Is it the shape or maybe the retina or maybe even differences in nerves?

Answer 1

part of it is the shape of the lens... this affects your nearsightedness or farsightedness. the distance from the lens to the back of your eye where the receptors are also makes a difference, because light rays bend as they move towards the back of the eye. there is no difference in nerves between human beings, unless you are born without certain cells. the lack of ganglion cells, or malfunction of them, for instance, is the reason that some people are colorblind-- there are certain cells that are highly specialized for seeing certain colors, and when they don't work, you can't see that color.

Answer 2

Wow. This covers A LOT of territory.

Far or near sightedness is mainly determined by the shape of the eye. The lens focuses all the light on a certain point. If the eye elongates or shortens the focal point will not line up perfectly with the retina (the part of the eye that detects light and is the first part responsible for image perception.)

Also, the cornea can become hazy, such as with cataracts. This limits the light that gets into the eye and obscures the vision.

Some people can have macular degeneration, optic nerve atrophy, retinal detachments, optic nerve compression from tumors. The list goes on and on.

The main difference, though is the shape of the eye.

Glasses change the focal point, the point where the light through the lens converges to a single point. If your eye is shortened, the optometrist or ophthalmologist will give you glasses to make the light converge earlier. If the eye is lengthened, they will make the lenses to that the light converges at a farther distance. Either way, they're trying to get the light to focus on the retina at the back of the eye.

I hope this wasn't too confusing.

Answer 3

Curvature of the cornea, refractory index of lens, length of the eye ball, muscles of the eye balls, blood and nerve supply to retina and genetically determined retinal changes jointly determine the acuity of vision, refraction ,field of vision and color vision.