The visual sense has maximum acuity at:

 # The visual sense has maximum acuity at :
A. Ora serrata
B. Optic disc
C. Macula lutea
D. Fovea centralis

The correct answer is D. Fovea Centralis.

At the posterior pole of the eye, 3 mm lateral to the optic disc there is another depression of similar size called the macula lutea. It is avascular and yellow in color. The center of the macula is further depressed to form the fovea centralis. This is the thinnest part of the retina. It contains cones only and it is the site of maximum visual acuity. 

The rods and cones are the light receptors of the eye. The rods contain a pigment called visual purple. They can respond to dim light (Scotopic vision). The periphery of the retina contains only rods, but the fovea centralis contains no rods. The cones can only respond to bright light (photopic vision) and are sensitive to color. The fovea centralis has only cones. 

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