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Q80 (CDS-I/2025) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Human anatomy physiology Answer Verified

The human eye has a point that lacks photoreceptor cells. This is identified as :

Result
Your answer: —  Â·  Correct: B
Explanation

The human retina contains millions of light-sensitive photoreceptor cells, namely rods and cones, which convert light into electrical signals [1]. However, there is a specific region on the retina called the optic disc where the optic nerve exits the eyeball to carry signals to the brain [1]. This area lacks all retinal elements except the nerve fiber layer and contains no photoreceptor cells (rods or cones) [6]. Because light incident on this specific point cannot be detected or elicit a response, it is physiologically identified as the 'blind spot' [6]. In contrast, the fovea is the region with the highest concentration of cone cells for sharp vision [5], and the orbit refers to the bony eye socket. Therefore, the point lacking photoreceptors is the blind spot.

Sources

  1. [1] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > 10.1 THE HUMAN EYE > p. 162
  2. [6] https://en.wikipedia.org/wiki/Optic_disc
  3. [3] https://en.wikipedia.org/wiki/Cone_cell
  4. [5] https://www.sciencedirect.com/topics/medicine-and-dentistry/optic-disc
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