third eyelid造句怎么写

Ocular tumors in dogs are found in the eyelid, conjunctiva, third eyelid, cornea, sclera, iris, ciliary body, retina, choroid, optic nerve, and orbit.

You may not know it, but you have a third eyelid.

If you watch a cat blink, you will see a white membrane cross its eye - that is called its third eyelid.