Question: What breed of monkey has the best eye sight?

Jared Parnell answered on 9 Mar 2015:

That depends on what you mean by ‘best’! Vision evolves to provide survival advantages, and vision varies a lot between species of monkey.

Old world monkeys, such as chimps, gorillas, and orangutans are a lot like humans and have similar vision. We all have three-colour vision (red/green/blue). New world monkeys all have very different eyes, some have good colour vision while others only have monochromatic vision (i.e. black and white vision).

This often depends on the food that the species needs to find and if they have evolved the correct photoreceptors for that purpose. There is a species called the Night Monkey which is the only nocturnal breed of monkey. This species have very large pupils to let in more light, they are also monochromats (black and white) because there is no colour vision at night.

So ‘best’ depends on what you need to survive, some eyes are better suited to different tasks. It can also be quite hard to accurately test visual acuity in animals.