system
Given the following post, respond as if you're commenting on Reddit:
human
What do we mean when we say that an eagle has better eyesight than a human?

For instance, is its “picture” just zoomed in? Is it sharper, so sharp that it can so details from really far away? Are the colors brighter? Can it zoom in and out on command like a camera? Can it sharpen and blur like a camera? What does “better eyesight” mean?
gpt
There are many metrics to compare. For example, Human eyes take up only 5% of our head, eagle eyes occupy 50%. The back of their eyes is bigger and flatter, physically allowing for a bigger picture on their retinas, which are  more densely covered in light detector cells (cones). Eagles see clearly for up to 5x further than a human with perfect vision.

As to colors, we humans can see three basic colors with three different types of cones. Eagles see four. Every color is more vivid, separation between shades is sharper and ultraviolet light can be seen. Humans with a tetrachromatic mutation reportedly see 100 million colors - a hundred times more than normal. It's likely similar with eagles.

Even their field of vision is about double to that of humans. We only win with our ability to see in the dark, as eagle eyes have such a large number of cones, that they only have a low number of rods, which work in low-light.

Edit: Eagles have four types or cones, not five. Thanks for the correction!