The eye is made of several layers of tissue, each with a specific function. These layers are arranged concentrically, like an onion.
Layers of the Eye
Exterior Layers
- Sclera: This is the tough, white outer layer of the eye that provides structural support and protection.
- Cornea: The clear, front part of the eye that allows light to enter.
Middle Layer: Uvea
The uvea is the vascular layer of the eye, responsible for nourishing its structures. It is divided into three parts:
- Iris: The colored part of the eye that controls the amount of light entering by adjusting the size of the pupil.
- Ciliary Body: This structure is involved in producing aqueous humor and also controls the focusing of the lens.
- Choroid: A layer between the sclera and the retina, rich in blood vessels that provide nutrients to the retina.
Innermost Layer: Retina
- Retina: This is the light-sensitive layer lining the back of the eye. It's made up of nervous tissue and contains photoreceptor cells (rods and cones) that convert light into electrical signals, which are sent to the brain via the optic nerve.
| Layer | Description |
|---|---|
| Exterior | Sclera (white part) and cornea (clear front) - protective and light-entry structures. |
| Uvea | Iris, ciliary body, and choroid - vascular layer for nourishment and focusing. |
| Retina | Nervous tissue layer at the back of the eye that contains photoreceptors, responsible for sight |
The eye’s complex structure allows it to perform its function of seeing. The layers work together to let light into the eye, focus it onto the retina, and translate the information into signals that are sent to the brain.
