Under proper correction, what is the distal point for both contact lenses and spectacles?

Study for the NBEO Physiological Optics Test. Prepare with flashcards and multiple-choice questions, each question has hints and explanations. Ace your exam!

Multiple Choice

Under proper correction, what is the distal point for both contact lenses and spectacles?

Explanation:
The distal point is the location in space from which an object must come so that a free, relaxed eye can form a clear image on the retina. When vision is properly corrected, the eye is effectively emmetropic, so distant objects can be focused with no accommodation. Light from objects at infinity enters the eye as parallel rays, and the relaxed eye can focus those rays onto the retina. That makes the distal point lie at infinity. This holds whether you wear contact lenses or spectacles—the correction makes the eye relaxed for distant vision; the difference between the two is mainly how close the optics sit to the eye, not the final distal point.

The distal point is the location in space from which an object must come so that a free, relaxed eye can form a clear image on the retina. When vision is properly corrected, the eye is effectively emmetropic, so distant objects can be focused with no accommodation. Light from objects at infinity enters the eye as parallel rays, and the relaxed eye can focus those rays onto the retina. That makes the distal point lie at infinity. This holds whether you wear contact lenses or spectacles—the correction makes the eye relaxed for distant vision; the difference between the two is mainly how close the optics sit to the eye, not the final distal point.

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