First, let’s take a look at what is a color lens.

   Single Vision Photochromic lens with blue cut, also known as "photosensitive lenses". Because silver halide chemicals are added to the lens, the originally transparent and colorless lens will turn into a colored lens when exposed to strong light for protection, so it is suitable for both indoor and outdoor use.

   The color-changing lens can automatically adjust the light transmittance according to the intensity of the light, so that the eyes are always in the best light state, and the comfort is greatly improved. The color-changing lens also solves the trouble that the sunglasses cannot be worn indoors and the glasses must be replaced frequently when entering and leaving the room. A pair of color changing mirrors do not need to be replaced indoors and outdoors, which brings great convenience to life.

The first trick: choose the color of the color changing lens。

It is mainly considered from the functional characteristics of the lens, the purpose of the glasses, and the personal color requirements.

1. Gray lens: can absorb infrared rays and 98% of ultraviolet rays. The biggest advantage of the gray lens is that it will not change the original color of the scene due to the lens, and the most satisfactory is that it can very effectively reduce the light intensity. The gray lens can evenly absorb any color spectrum, so the scene will only become darker, but there will be no obvious chromatic aberration, showing a real and natural feeling. It is a neutral color, suitable for all people.

2. Pink lens: This is a very common color. It can absorb 95% of ultraviolet rays. If it is to correct vision, women who must wear them often should choose light red lenses, because light red lenses absorb ultraviolet rays better and can reduce the overall light intensity, so the wearer will feel more comfortable .

3. Brown lenses: can absorb 100% of ultraviolet rays, brown lenses can filter out a lot of blue light, can improve the visual contrast and clarity, so it is very popular with wearers. Especially when the air pollution is serious or foggy, the wearing effect is better. Generally, it can block the reflected light from a smooth and bright surface, and the wearer can still see the subtle parts. It is an ideal choice for drivers. For middle-aged and elderly patients with high vision above 600 degrees, priority can be given.

4. Green lens: The green lens, like the gray lens, can effectively absorb infrared light and 99% of ultraviolet light. While absorbing light, it maximizes the green light reaching the eyes, so it has a cool and comfortable feeling, suitable for people who are prone to eye fatigue.

5. Yellow lens: can absorb 100% of ultraviolet rays, and can let infrared and 83% of visible light penetrate the lens. The biggest feature of yellow lenses is that they absorb most of the blue light. In foggy and twilight hours, yellow lenses can improve contrast and provide more accurate vision, so it is also called night vision goggles. Some young people wear "sunglasses" with yellow lenses as a decoration. Glaucoma patients and patients who need to improve visual brightness can choose.

The second measure: Identify the quality of the color changing lens

(1) The surface of the high-quality color-changing lens has no scratches, abrasions, rough surfaces, pits, and the lens is obliquely obliquely facing the light, and the finish is extremely high. There are no spots, stones, streaks, bubbles, cracks inside the lens, and the lens is bright.

(2) The two lenses of the color-changing glasses must be of the same color without difference.    The color change must be uniform, and it cannot show several colors. There is no "yin and yang color". The color change time is fast when it sees sunlight, and when there is no sunlight, the color fade time is also fast. Inferior lenses change color slowly and fade quickly, or change color quickly and fade slowly. The worst color changing glasses do not change color at all.

(3) The thickness of the two lenses of the color-changing lens should not be too different, otherwise, it will affect the vision and damage the health of the eyes. The thickness of the single lens should also be uniform. If it is a color-changing plan lens, the thickness should be about 2mm with smooth edges.

(4) There is no sensation when wearing, no dizziness or swelling, no blur or deformation of the observed object. When buying, hold the glasses, look through the lens with one eye, look at the distant objects, shake the lens up and down, left and right, the distant objects should not have the illusion of movement.