Visible light is the range of light visible to the human eye.

This lens is used for light concentration.

This lens is used to concentrate light.

He likes to take a walk in the park at dusk.

Let's calculate the inscribed circle of this polygon.

This shape is called a bicone.

We should always remember the power of Kannon in difficult times.

Koushirou is my best friend.

Kou Sennen is my best friend.

Photochemistry is a branch of science that studies how chemical reactions proceed under the influence of light.