system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If looking through a periscope, would a short-sighted person be able to see less far than a normal person?
gpt
In a simple, mirrors-only periscope a near-sighted person would need their glasses otherwise everything would appear blurry.

However, more modern periscopes use lenses for focus and/or magnification, so they can be individually focused based on your eyesight like binoculars or a telescope.