Why do objects underwater look closer?

Answer: Refraction bends light rays upward

Pressure changes perception — Wrong. Pressure doesn't affect perception. Objects appear closer because refraction bends light rays as they exit water, changing the angle.

Refraction bends light rays upward ✓ — Correct! When light from underwater objects exits water into air, it bends away from the normal (water is denser, refractive index ~1.33). This makes light rays appear to come from a shallower, closer location. A fish 4 feet deep appears only 3 feet deep! This is why spearfishing requires aiming below the apparent position.

Eyes adapt to water medium — Wrong. Eyes don't adapt to change physics. Refraction at the water-air interface bends light, making objects appear closer than they actually are.