A mirror swaps left and right in reflections, though it really reverses front and back.

The longer version

A mirror does not swap left with right; it reverses the direction perpendicular to its surface. Light from the nose travels a shorter round trip than light from the back of the head, so the image is flipped front to back, and everything else follows from that.

The left-right story comes from interpretation. Because the reflected figure faces the opposite way, people mentally rotate it to compare, and the rotation introduces the apparent swap. Text looks reversed for the same reason: the letters are turned away, not rearranged sideways. Two mirrors at right angles restore the original handedness.

Where this entry sits

These facts explore how light behaves and how human eyes turn it into the colors we see. Along the way you meet rainbows, prisms, mirrors, shadows, lasers, and optical tricks that fool our vision every day. The full list sits on the Color and Light page, where every entry is listed in order.

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More From Color and Light

Eight more entries

Kaleidoscopes create symmetrical patterns by reflecting light between angled mirrors inside a tube.

Water bends light, which makes a straight straw in a glass look broken or shifted.

Mirages appear on hot roads when layers of air bend light from the sky toward the ground.

A rainbow is actually a full circle, but the ground usually hides the lower half.

Double rainbows happen when light reflects twice inside each droplet, reversing the color order.

You never see a rainbow from directly overhead because the geometry requires looking away from the sun.

Red light bends least through glass, while violet light bends the most.

The color orange takes its name from the fruit, which had the word first.

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