cornea
It is called a nictating membrane.
The clear transparent protective coating over the front part of the eye is called the cornea. It is responsible for focusing light into the eye and protecting the eye from dust and other particles.
Don't know what you mean by 'serious.' Do you mean 'serous' as in fluid-filled? The membrane that can cover over a frog/toad's eyes (and other amphibian, reptile, even mammal species) is known as a 'nictating' membrane. It is there to protect against fluid and debris from coming into contact with the corneal surface of those eyes.
cornea
myothelial tiisue
The cornea, or clear layer on the front of the eye.
cornea mean the transparent front part of the eye iris and the pupil.
The transparent layer forming the front eye
The nictitating membrane is the transparent layer the covers the outside of a frogs eye. Frogs have a so-called Nictitating membrane, which they can slide over their eyes for protection. They do this while jumping and swimming.
The front clear surface of the eye is called the cornea. It protects the covering of the eye and helps to focus light.
The cornea is responsible for focusing the light that enters the eye. It is the transparent portion of the eye that covers the front of the eye
The transparent skin in front of your retina.