Sunglasses can be divided into shade by use of mirrors, light-colored sunglasses, and three types of special-purpose sunglasses.
  The so-called sun mirror, suggests that it is for shade purposes, people often rely on the adjustment in the sun to adjust the size of the pupil luminous flux, when the light intensity of more than ability to regulate the human eye, it will cause harm to the human eye. So in outdoor activities, especially in the summer, many people use sun mirror to block the sun, the eyes adjust to reduce glare caused by the irritation caused by fatigue or injury.
   Light-colored sunglasses, blocking the sunlight as the sun mirror, but its rich colors, suitable for use with various types of clothing with, has a strong decorative effect. Light-colored sunglasses because of its rich colors, styles, by the young people of all ages, women's fashion is fallen in love with it. Special purpose sunglasses block the sunlight has a strong functions, commonly used on the beach, skiing, hiking, golf and other outdoor more intense sunlight, the UV performance and other indicators have higher requirements.
   Different groups of people, depending on the preferences and choose sunglasses for different purposes, but the most fundamental thing is to protect the wearer from safety and vision does not damage the basic principle. Reduce the light stimulation, visual clarity without distortion, anti-UV, no distortion of color recognition, accurate traffic signal recognition, should be the basic functions of sunglasses. If there are defects in these functions, ranging from the role of lost sunglasses, weight will produce dizziness, eye soreness and other symptoms consciously meet, sometimes there will be a slow, walking debate color illusion and visual symptoms and lead to accidents inequality and so on. So I chose to focus on style and sunglasses can not just ignore its inherent quality.