The anterior portion of the sclera is called:

What is a characteristic feature of the human cornea?

Identify the part of the eye concerned with the following two sentences in the given figure. Which alphabet is used to indicate this part?
$1$. It is the coloured visible part of the eye.
$2$. It is a pigmented and opaque structure.

The retinal blood vessels enter the eye at

When the object is at a distance of more than $6 \text{ metres}$,at that time

Astigmatism occurs when...