The eye is an organ which gives you vision, thanks to its photoreceptors, which detect light.
The eyes sit in the bony orbits, which deflect impacts and protect them. The eyes have anatomical layers, including the fibrous, vascular, and inner layers, and each of these layers has specialized structure and function.
The cornea and sclera comprise the dense, fibrous layer of the eyes. They’re continuous with each other and give the eyeball shape and structure. The sclera provides an attachment site for your extraocular muscles. The extraocular muscles are found at the sides of the eyeball and implement all of your eye movements. When light passes through the cornea, its round shape bends the light’s path, focusing it inside the eye.
Under the fibrous layer is the eye’s vascular layer, which has three components - the ciliary body, choroid, and iris. The choroid is a layer full of blood vessels which supply the retina, which is found beneath the choroid! The iris controls the pupil, which acts as an aperture, shrinking and growing the pupils via smooth muscle fibers. The ciliary body has two parts - muscles and processes. The muscle attaches to the lens by the processes. The ciliary body also makes aqueous humour and it is attached to the lens and can change its shape, resulting in a change in focal length.
When light reaches the inner layer, it is detected to give you sight. The retinas are your eyeball’s sensors, and photoreceptors are found within it. Each retina is composed of two layers. The neural layer is thicker and is used for detecting photons, while the thinner pigmented layer maintains the retina and absorbs stray light that might interfere with the image captured by the neural layer. In the front, the eye’s inner layer is called non-visual, since only the pigmented layer is present, while in the back, the eye’s inner layer is termed the retina’s optic part, since it is here that one has both retina layers. At the retina’s center is the macula, and at its center is the fovea centralis. The fovea has high photoreceptor density, providing the sharpest visual acuity! Near the fovea, you have your blind spot. Here, there are no photoreceptors, since this is where the optic disk sends signals backwards via the optic nerve.
Behind the lens we find transparent gel called the vitreous body, which fills space in the posterior chamber. A canal runs from the optic disc to the lens through this gel. It is a fetal remnant called the hyaloid canal. Remember that while the vitreous body is in the posterior chamber, the aqueous humour is in the anterior chamber. The lens is between the vitreous body and the pupil.
3D model from: www.turbosquid.com/3d-models/...