Have you ever had an experience where you feel it is difficult to see the license plate number of a car and highway road when driving at night or you feel it is difficult to see the sign of road and people’s faces when walking at night?

According to the size of the pupil, if more lights enter the eyes, people will feel dazzling, or they cannot read nearby words (especially for people over 40 years old). These symptoms will appear when the pupil enlarges at night or in dark places.

That is why people feel “dazzling!!!” when lights into the eyes such as headlights of cars and flashlights in dark places.

Illustrated by diagram, the entry of light varies depending on the size of the pupil. In picture 1, the focus is on the retina (camera film), while in picture 2, the focus is in front of the retina.
The state as shown in picture 2 is also called nocturnal myopia.

This is a physiological phenomenon, not abnormal.
In order to reduce the dazzling and invisible feeling at night, some people wear night sunglasses, but it is difficult to solve the problem of pupil enlargement at night.
When driving or walking at night, avoid looking directly at the headlights of the opposite car, look away from the headlights to improve the night vision.