Relevant standard
Ultraviolet protection factor (UPF)
Definition: UPF is a measure of the ability of a fabric or material to block ultraviolet light, and in the case of sunglasses, it reflects the ...
Metal material
peculiarity
Titanium alloy: with light weight, high strength, corrosion resistance, no allergic reaction and other advantages, is a common material for high-end spectacle frames. It ...
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...
The color depth of sunglasses and eye protection ability is not a simple positive correlation, the following is the specific analysis:
Sun glasses color action principle
The color of sunglasses is ...
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 ...
Optometric data
Accurate degree: Go to a professional eye institution or optician for optometry to obtain accurate myopia, farsightedness, astigmatism degree and axial position data. This is the ba...
