Concept: This question tests knowledge about the structure of the human eye and which specific part is transplanted during an eye donation.

Why (A) is correct: In eye donation, only the cornea, the transparent front part of the eye that covers the iris, pupil, and anterior chamber, is utilized. It is transplanted to a recipient whose cornea is damaged or diseased, causing vision impairment. The cornea is avascular (lacks blood vessels), which reduces the chances of immune rejection, making it ideal for transplantation.

Why other options are wrong:

• (B) Lens: The lens is inside the eye and is not typically transplanted in eye donation; cataracts (clouding of the lens) are treated by replacing the lens with an artificial one, not a donor lens.
• (C) Iris: The iris is the colored part of the eye that controls pupil size; it is not transplanted.
• (D) Retina: The retina is the light-sensitive tissue at the back of the eye; retinal damage is complex and not currently treated by whole retina transplantation from a donor.

Common Mistake: Students might confuse eye donation with donating the entire eyeball. It's crucial to remember that only the cornea is transplanted.

NEET Tip: Focus on the specific parts of organs involved in transplantation procedures, as these are common exam questions. For the eye, remember 'Cornea for Donation'.

Correct Answer: (A)