Anatomy question?

Question

Does anyone know what the light-bending media of the eye are? There are two answers that I am having difficulty locating...thanks.

Answer 1

Strictly, light is bent (refracted) at the *junction* of two media with different refractive indices.

Inside a uniform media, of whatever optical density, light travels in straight lines.

The major refracting surface for the eye is the tear/ air layer, the tear film taking its curved shape from the underlying cornea.

The tear/cornea interface has no real power, and the rear cornea/aqueous one a very minor effect.

(as shorthand, and for most practical purposes, these are taken as a single figure:  "In the mechanism of image formation on the retina, cornea and the lens act as strong convex lens. The converging power of the normal eye is slightly less than +60D and contribution of cornea in an average subject is about +43D." Duke-Elder, S., 1970, System of Ophthal.) ,

The crystalline lens delivers about 25% of the eye's overall optic power, with its two curved surfaces: aqueous/lens at the front, lens /vitreous at the back.

Answer 2

the lens and the cornea :)

Answer 3

The lens and the pupil.

  The pupil bends the lens to accomdate the light that is present that helps us to see an object and it is the pupil that regulates the light that come into the eye.

   This is why when we reach the age of 40 we start having focusing problems that we had never had before.  

   The lens is getting denser and it is harder for the pupil to bend the lens.

Answer 4

1) Cornea, the main refracting surface (~75%)

2) Crystalline lens, the secondary refracting surface (~25%)

Answer 5

Tears

Cornea

Aqueous

Crystalline lens

Vitreous Humour

Techs who work with Ophthalmologists are not reliable sources of information concerning the eye.

Answer 6

they might be referring to the cone.