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.

There is a state-of-the-art electron microscope in my laboratory.

The Yata no Kagami is a sacred mirror that appears in Japanese mythology.

He monitored the enemy's movements using a periscope.

I used an optical microscope for an experiment at school.

When I look into her eyes, it's like I can see her heart. That's because the eyes are the window to the soul.

He was born and raised in South Hamgyong.

He was born and raised in North Hamgyong.