If something really small with eyes, like an ant, were to stumble upon something very small humans can’t see, would they be able to see it?
In: Biology
Other commenters have accurately pointed out that many microscopic organisms don’t have eyesight per se, and use other means of sensing to detect objects around them.
Of animals that do have eyesight, it is not the size of the animal that determines the size of object which can be seen with the naked eye – it is the magnification and proximity.
Magnification:
Some animals have the ability to magnify objects more than humans can by essentially flexing muscles in their eyes to change the shape of their lens, as well as having good reactions to light which help narrow and focus their vision (birds of prey can do this, for example). So if you and a hawk were flying along at the same height, they could see smaller things than you could, because they have better magnification.
Proximity:
If animals are very small and close to the ground, they may be able to pick out smaller objects and see in more detail because they are closer to them than you are. If you and an ant are both looking at the same patch of ground, and you are standing up, the ant may be able to pick out details that blend into the background for you. If you were to lie down on the floor and look at a very small patch of ground, you would be able to pick things out in roughly the same amount of detail, because you are much closer to the same proximity to the ground.
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