Explanation:

The image formed on the retina of a human eye is 1 Virtual and inverted 2 Virtual and erect 3 Real and erect 4 Real and inverted. The iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina.Eye color is defined by that of the iris. The cornea represents the strongest part of the refracting power of the eye, providing about 80% of the power of the system. The index of refraction of the cornea is about 1.376. Rays pass from the cornea into the watery fluid known as the aqueous humor which has an index of refraction of about 1.336, so most of the refraction is at the cornea-air interface.