Parallel Rays Focus on Retina in Emmetropic Eye

Steps:

• Distant objects emit parallel light rays toward the eye.
• Cornea and lens refract these rays to converge.
• In a normal (emmetropic) eye, rays focus exactly on the retina.
• Choose diagram showing parallel incoming rays meeting at a point on the retina.

Why A is correct:

• It illustrates parallel rays from infinity converging to a real, inverted image on the retina, matching the definition of emmetropia where focal length equals axial length.

Why the others are wrong:

• B: Rays remain parallel or diverge after lens, failing to form a focused image on retina (astigmatism or accommodation error).
• C: Rays converge before retina, indicating hyperopia (farsightedness).
• D: Rays converge behind retina, showing myopia (nearsightedness).

Final answer: A