The lens is avascular and nourished by diffusion from the aqueous and vitreous

uberon

ocular lens, lenses, crystalline lens

The eye of the adult lamprey is remarkably similar to our own, and it possesses numerous features (including the expression of opsin genes) that are very similar to those of the eyes of jawed vertebrates. The lamprey's camera-like eye has a lens, an iris and extra-ocular muscles (five of them, unlike the eyes of jawed vertebrates, which have six), although it lacks intra-ocular muscles. Its retina also has a structure very similar to that of the retinas of other vertebrates, with three nuclear layers comprised of the cell bodies of photoreceptors and bipolar, horizontal, amacrine and ganglion cells. The southern hemisphere lamprey, Geotria australis, possesses five morphological classes of retinal photoreceptor and five classes of opsin, each of which is closely related to the opsins of jawed vertebrates. Given these similarities, we reach the inescapable conclusion that the last common ancestor of jawless and jawed vertebrates already possessed an eye that was comparable to that of extant lampreys and gnathostomes. Accordingly, a vertebrate camera-like eye must have been present by the time that lampreys and gnathostomes diverged, around 500 Mya.[well established][VHOG]

UBERON:0000965

This class excludes compound eye corneal lenses.

• epithelium of lens

• camera-type eye

• lens placode

• capsule of lens

• vertebrate lens cell
• capsule of lens
• epithelium of lens
• lens nucleus
• lens cortex