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

The ELI5 is our eyes see in standard definition, and theirs see in 4k UHD.

I noticed this effect when I got laser eye surgery and came out of it seeing 20/10. Everything in the middle distance looked like it was in HD; I could see mortar joints in brick buildings that had previously just been a brick-colored wall at that distance.