The eye is the structure that allows us to see.
It contains many parts, but we will not be discussing all of them in this post.
The most important ones are the cornea, iritis and pupil. One interesting thing about these three structures is their order from front to back: the cornea first, then iritis and finally the pupil.
A ray of light entering the eye will encounter these structures in which order?
The cornea first, then iris and finally pupil.
This is important for determining refractive power of lens as it bends light to focus on retina.
The front three layers are transparent like a window so that they can allow light to pass through them without being distorted by anything else in the eye.
These include: Cornea, Crystalline Lens (inside the eye), Vitreous Humor(behind lens). Other parts have different functions but all contribute towards focusing an image onto the retina at various points along its surface area or volume called fovea centralis.
Where there is a high density of cone cells with photopigments sensitive.