Question

Only rods are present in the eyes of which one of the following animals?
a) Pigeon
b) Squirrel
c) Fowl
d) Owl

Answer 1

Hint: Rods and cones are the photoreceptors present in the eye. They are helpful in forming a picture of the things seen by the eye. Rods are used in dimly lit areas as they work best in low-intensity light areas.

Complete answer:
Only rods are present in the eyes of the owl. They have densely packed rods which are dominant in the eye. As rods are responsible for providing good vision in the low-intensity light so they help owls to see during the night time more clearly. Owls can’t see in total darkness as they need some source of light to spot nearby objects. The eyes of the owl provide a binocular vision that helps in enhancing the depth of perception and focusing on prey only.

Additional information:
- Pigeons have very well-developed eyes. They can see a wide spectrum of colors. Also, they have the ability to see larger views which can extend up to 360 degrees. They can also see polarised light. Pigeons have a rod photopigment named as rhodopsin and iodopsin which help them see things in the surroundings.
- Fowl have a better vision than human beings. They have five types of light receptors in their eyes. Their night vision depends on the rods and the daytime vision depends on the cones.
- Squirrels have quite good eyesight. Their peripheral vision is good and also their focal eyesight is good. They have both rods and cones present in their eyes.
The answer is ‘d) Owl’.

Note: Rods are responsible for the night vision and cones are responsible for the daylight vision. Cones can perceive bright colors well. The absence of cones may lead to less distinct visually.