Question

Differentiate between rods and cons?

Answer 1

Rods are accountable for vision at low light levels (scotopic vision). Rods do not mediate color vision and have a low spatial acuity whereas Cones are active at higher light levels (photopic vision), and are capable of color vision along with being accountable for high spatial acuity.

Complete answer:
Differences between rods and cones are as follows -

BASIS FOR COMPARISON	RODS	CONES
Meaning	Rods are one of the photoreceptors seen in the eye that have a rod-like structure and provide twilight vision.	Cones are also photoreceptors present in the eye, that are fewer in number and are of the cone shape.
Location	Rods are usually found around the boundary of the retina.	Cones are usually found in the center of the retina.
Amount	Rods are about 120 million photoreceptors out of the total 125 million photoreceptors in the human eye.	Cones are 5 million photoreceptors.
The shape of the outer segment/Pigment	The outer segment is cylindrical of Rods which include rhodopsin pigment, made up of Vitamin A.	The outer segment is conical of Cones which comprises iodopsin pigment.
Colour vision	Rods cells do not give color vision and do not have any differentiation.	Cones give color vision and are of three types: green, blue, and red.
Disease/Deficiency	Lack of pigment in the rods, known as rhodopsin causes night blindness.	Lack of pigment in the cones, known as iodopsin causes color blindness.

Note: Rods are not good for color vision. As in a dim room, we mainly use our rods, but we are "color blind." Rods are more abundant than cones in the periphery of the retina. This is because the cones are used for color vision and are better suited for detecting fine details. There are nearly 6 million cones in the human retina.