corneal eye

The cornea is a transparent, dome-shaped membrane covering the front of the eye, measuring about 12 mm in diameter. It lacks blood vessels but is rich in nerves, making it sensitive to touch and pain. The cornea is nourished by tears and aqueous humor and serves as the eye's primary focusing element, refracting light before it reaches the lens. It protects the iris and pupil from foreign objects. The cornea consists of five layers: the epithelium, Bowman's membrane, the stroma, Descemet's membrane, and the endothelium. The epithelium, the outermost layer, acts as a barrier against infection and heals quickly from scratches. The stroma, the thickest layer, is composed of regularly arranged collagen fibers that ensure transparency. Damage to these fibers can lead to opaque scars. The endothelium, the innermost layer, regulates fluid balance within the cornea, preventing swelling. Loss of endothelial cells can impair vision and may necessitate a corneal transplant.12