Scleral cartilage

The scleral cartilage is a type of cartilage that develops within the sclera, the dense, fibrous outer layer of the vertebrate eye. It is found in many vertebrate groups, including birds, most other reptiles, teleost fishes, and cartilaginous fishes, but is absent in placental mammals and has been secondarily lost in groups like snakes.

The primary function of scleral cartilage is to provide structural rigidity to the eyeball. This helps maintain the eye's shape, supports the attachment of extraocular muscles, and in some species, aids in visual accommodation.