What does it mean when scientists say “an eagle can see a rabbit in a field from a mile away”. Is their vision automatically more zoomed in? Do they have better than 20/20 vision? Is their vision just clearer?

Question

What does it mean when scientists say “an eagle can see a rabbit in a field from a mile away”. Is their vision automatically more zoomed in? Do they have better than 20/20 vision? Is their vision just clearer?

In: Biology

Answer 1

It’s not necessarily more “zoomed in”. Rather, think of it as being able to better discern small detail. When you’re at the optometrist and you look at that chart of progressively smaller letters, they get blurry and less distinct the smaller they are. But an eagle would be able to discern much smaller letters (and would see them as much less blurry) if they could read. This helps them tell the difference between little grey mice and little grey stones from way high in the air.