Classification of glasses lenses
CLASSIFICATION OF LENSES
- By material
- After design
- After treatments
- After use
1. AFTER MATERIAL
- Mineral Glass (Glass)
- Organic glass (plastic)
- Recommended for certain activities (welding, high temperatures, smelters, etc.).
- Cheap, but it breaks easily.
- It can only be carried on a whole frame.
- lightweight (up to 50% lighter than glass).
- Not breakable.
- You can choose any kind of frame
1.3. POLICARBONATE / TRIVEX
- Resistant to MECHANICAL SHOCK / certain activities: motorcyclists, athletes.
- Recommended for rimless frames.
- Do not break and are very lightweight..
2. AFTER DESIGN
- Double aspherical
- are standard lenses (curved surface).
Aspheric / double aspheric:
- Are lenses with flattened surface;
- Provides superior optical benefits;
- flattening of the lens surface is aesthetically increased by up to 40% compared to a spherical lens;
- Greater field of view;
- Better image;
- Image closer to the image of the healthy eye;
- Increased visual comfort.
3. LENSES THICKNESS
Lens thickness = refractive index
The higher the index of refraction, the thinner the lens is.
The standard index is 1.5 and the thinnest lens has 1.74 (for existing products in Romania).
4. 4. SPECIAL COATINGS
Durification coating: Applies only to plastic lenses and has the role of better protecting the lens against scratches.
Anti-reflective coating: is the treatment that increases the transparency of the lens by eliminating the “window” effect appearing on the lens surface, especially in environments with artificial illumination and / or computer use.