Yes, when the eyelids are closed, they cover the entire eyeball including the posterior portion. This helps protect the eye from external elements such as dust and debris.
The outer transparent protective cover of the eyeball is the cornea. It helps protect the eye and refracts light to focus it on the retina at the back of the eye.
If your eyeball falls out, it is crucial to seek medical help immediately. Keep the eyeball moist and clean using a sterile saline solution if available. Avoid touching or trying to push the eyeball back in yourself.
Fish do not have eyelids like humans do, so they cannot blink in the same way. However, some fish have a nictitating membrane that can cover their eyes for protection. This membrane acts like a thin, transparent eyelid and helps keep the eye moist.
isn't it iron oxide, i don't know
No. While Hurricane Sandy covers a significant portion of the eastern U.S. it will never be anywhere near big enough to cover the whole country. Not that the storm has made landfall it will weaken and dissipate in a few days.
sclera
eyelids and eyelashes
eyelids and eyelashes
eyelids
Actually, snakes don't have eyelids. They have scales that cover their eyes. When they molt, the scales on their eyes are replaced.
Actually, snakes don't have eyelids. They have scales that cover their eyes. When they molt, the scales on their eyes are replaced.
The outer transparent protective cover of the eyeball is the cornea. It helps protect the eye and refracts light to focus it on the retina at the back of the eye.
OPERCULUM
This portion of the conjunctiva covers the anterior part of the sclera (the "white" of the eye). The bulbar conjunctiva stops at the junction between the sclera and cornea; it does not cover the cornea. Palpebral conjunctiva. This portion covers the inner surface of both the upper and lower eyelids.
I think it is called a 'Nictating Membrane'.
Snails have long stalks which hold there eyes up and the eyeball has no cover so it HURTS!
Conjunctivitis is inflammation of the conjunctiva. The conjunctiva is a layer of epithelial cells that cover the sclera (in the eye) and the inside of eyelids.