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1.56 High Definition ASP HMC Green Coating Optical Lens - China Suppliers and Factory for Superior Vision Solutions
Data
| Product | High Definition lens | Index | 1.553 |
| Material | Resin | Abbe Value | 34 |
| Diameter | 65/70 | Coating | HMC Green coating |
Performance
Anti-fingerprint
Waterproof
High transmittance
Wear resistance
Anti reflection
UV protection
Lens refractive index
It refers to the ratio of the propagation speed of light in vacuum to the propagation speed of light in the lens material.
It reflects the refractive power of the lens towards light.
The higher the refractive index, the stronger the refractive power of the lens towards light.
When choosing the refractive index of a lens, the following factors can be considered:
Degree:
- For low myopia below 200 degrees, a refractive index of 1.50 or 1.56 can be chosen;
- For myopia between 200-400 degrees, a refractive index of 1.56 or 1.60 can be chosen;
- For myopia between 400-600 degrees, a refractive index of 1.60 or 1.67 is more suitable;
- For high myopia at 600-1000 degrees, it is recommended to choose a refractive index of 1.67 or 1.71.
- For myopia exceeding 1000 degrees, glass lenses with refractive indices of 1.71 or 1.74, or even higher, can be considered.
Frame Size:
If you choose a larger frame, in order to ensure that the edges of the lens are not too thick, you may need to choose a slightly higher refractive index.
The relationship between the refractive index of lenses and the thickness and weight of lenses:
Assuming all other parameters are the same, the higher the refractive index of the lens, the thinner the edge thickness of the lens, and the lighter the lens.
Advantages and disadvantages of different refractive indices:
- High refractive index lenses can make the lenses thinner, lighter, and more comfortable to wear.
- However, high refractive index lenses are usually more expensive and the dispersion phenomenon may be more pronounced.
- With the advancement of material technology, this law is gradually being broken.
- For example, the Abbe number of lenses with a refractive index of 1.71 is higher than that of most lenses with a refractive index of 1.56 and 1.67.
Frequently Asked Questions
What is the refractive index of a lens?
It refers to the ratio of the propagation speed of light in a vacuum to the propagation speed of light in the lens material. It represents the refractive power of the lens towards light; a higher index means stronger refractive power.
How does the refractive index affect the thickness and weight of lenses?
Assuming all other parameters are identical, a higher refractive index results in a thinner edge thickness and a lighter weight, making the lenses more comfortable to wear.
What refractive index should I choose for a high myopia prescription?
For high myopia between 600-1000 degrees, it is recommended to choose a refractive index of 1.67 or 1.71. For prescriptions exceeding 1000 degrees, refractive indices of 1.71, 1.74, or higher glass lenses are recommended.
Does the size of my glasses frame affect the choice of refractive index?
Yes. If you select a larger frame, you may need to choose a slightly higher refractive index to ensure the outer edges of the lens do not look too thick.
Are high refractive index lenses always better?
While they make lenses thinner and lighter, they are usually more expensive, and dispersion may be more pronounced. However, newer materials like 1.71 index lenses break this rule by offering a higher Abbe number than 1.56 and 1.67 lenses.