Frame width
Too wide: If the frame width is too large, the glasses are easy to slide on the face, especially in some light exercise or facial sweat, this situation will be more obvious. At the same...
Effect of refractive index on visual acuity in the aged
Lens thickness
For the elderly with high myopia or farsightedness, it is more appropriate to choose a lens with a high refractive index. The ...
Glass lens
Refraction: The refractive index of glass is high, generally between 1.5-1.9. This makes the glass lens have a strong ability to refract light and can more accurately control the directi...
Metal, TR90 and other materials of the sunglasses frame is more durable, the following is the specific analysis:
Metal material
Strong and durable: The metal has high strength and hardness and is n...
Choose the right product
Uv protection function: UV damage to children’s eyes is greater, to choose sunglasses that can effectively block UV, the label is usually marked with UV400 and other ...
Feel with the eye
Clarity: After wearing glasses, under the normal eye distance, such as looking at an eye chart at 5 meters or a book or computer screen at 30-40 centimeters, you should be able to...
