system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does reading small text hurt our eyes instead of making them stronger?
gpt
Your eyes have muscles to point them in the direction you’re looking, and small text doesn’t take up much space in your field of vision, so those muscles need to work hard to keep your eyes pointed at the small text.

The muscles just get tired working continuously, but it’s not like it’s a strength exercise that’s going to build them up like your arms.