Sunglasses can generally be divided into three categories based on their purpose: sun visors, light colored sunglasses, and special purpose sunglasses.
The so-called sunshade, as the name suggests, is used for shading. People usually need to adjust the size of their pupils to adjust the light flux under sunlight. When the light intensity exceeds the human eye's ability to adjust, it can cause harm to the human eye. So in outdoor activities, especially in summer, many people use sunshades to block out sunlight, in order to reduce eye fatigue or damage caused by strong light stimulation.
Light colored sunglasses are not as effective in blocking sunlight as sun visors, but they have rich colors and are suitable for use with various types of clothing, with a strong decorative effect. Light colored sunglasses are favored by the young generation due to their rich colors and diverse styles, and are particularly favored by fashionable women. Special purpose sunglasses have a strong ability to block sunlight, and are commonly used in fields with strong sunlight such as beaches, skiing, mountain climbing, golf, etc. Their UV resistance and other indicators have high requirements.
Different groups of people choose sunglasses based on their preferences and purposes, but the most fundamental principle is to ensure the safety of the wearer and prevent damage to their vision. The basic functions of sunglasses should be to reduce strong light stimulation, maintain clear and undistorted vision, prevent UV radiation, recognize colors without distortion, and accurately recognize traffic signals. If the above functions are defective, it can cause symptoms such as dizziness, eye soreness, and discomfort. Sometimes, it can also cause symptoms such as slow response, color discrimination illusion, unequal walking vision, and traffic accidents. So choosing sunglasses should not only focus on style but also ignore its inherent quality.