| Customization: | Available |
|---|---|
| Usage: | Lighting, Medical, Optical |
| Type: | Convex Lens |
|
Still deciding? Get samples of US$ 1/Piece
Request Sample
|
Suppliers with verified business licenses
Audited Supplier Audited by an independent third-party inspection agency
The lens index refers to the index of refraction (otherwise known as refractive index) of lens material for eyewear. It is a relative measurement number that describes how efficiently the material bends light. Light refraction will depend on how quick light itself passes through the lens.
Refractive Index
Lens materials are classified on their refractive index. This refractive index is the ratio of the speed of light when it travels through air to the speed of light when it passes through the lens material. It is an indication of how much light is bent as it travels through the lens. Light is refracted, or bent, at the front surface of the lens, then again as it exits the lens.A denser material bends light more, so not as much material is needed to achieve the same refractive effect as a less dense material. Hence the lens can be made thinner, and also lighter.
With regular eyeglasses lenses, the center of the glasses is thinner and the outer edges are thicker to facilitate refraction which is what makes prescription glasses work! High index lenses have a higher index of refraction than regular lenses, which means they don't need to be as thick around the edges to be effective.
High-index lenses mean that the lens itself can be both thinner and lighter. This allows your glasses to be as fashionable and comfortable as possible. High-index lenses are particularly beneficial if you have a strong eyeglass prescription for nearsightedness, farsightedness, or astigmatism. However, even those with a low eyeglass prescription can benefit from high index lenses.
What Is Blue Light?
Sunlight contains red, orange, yellow, green and blue light rays and many shades of each of these colors, depending on the energy and wavelength of the individual rays (also called electromagnetic radiation). Combined, this spectrum of colored light rays creates what we call "white light" or sunlight.
Without getting into complicated physics, there is an inverse relationship between the wavelength of light rays and the amount of energy they contain. Light rays that have relatively long wavelengths contain less energy, and those with short wavelengths have more energy.
Rays on the red end of the visible light spectrum have longer wavelengths and, therefore, less energy. Rays on the blue end of the spectrum have shorter wavelengths and more energy.
The electromagnetic rays just beyond the red end of the visible light spectrum are called infrared - they are warming, but invisible. (The "warming lamps" you see keeping food warm at your local eatery emit infrared radiation. But these lamps also emit visible red light so people know they are on! The same is true for other types of heat lamps.)
On the other end of the visible light spectrum, blue light rays with the shortest wavelengths (and highest energy) are sometimes called blue-violet or violet light. This is why the invisible electromagnetic rays just beyond the visible light spectrum are called ultraviolet (UV) radiation.
FAQ
| 1. Could you provide samples? |
| Of course, free samples can be sent to you, but please help us pay the freight fee. |
| 2. What Certification do you have for your optical lens? |
| FDA, CE, ISO9001 certification is available. |
| 3. What is the MOQ of optical lens? |
| We dont have Min Order quantity requirement. But if the quantity order is too small, we have to charge extra delivery fee. |
| 4. Could you provide OEM service? |
| Sure, just send us your requirements. |
){kind=link}