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Glass
- Glass is the traditional material for providing stable and precise optics.
- Glass in their natural state have little resistance to impact but has the advantage of being more difficult to scratch.
- Thinner glass lenses can be made for very high minus power (with refractive index of 1.8 and 1.9).
- Glass lenses are nowadays becoming outdated since they tend to be heavier than plastic lens and they are unsafe to wear because of its possibility of breakage.
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Plastic
- Lenses are made up of special resin called Columbia Resin.
- These are safe lenses to use for all age groups.
- Lenses are less likely to break.
- Lenses are 50 % lighter and comfortable than glass.
- Can be tinted to required colour.
- Can be coated to resist from scratches and to increase the light transmission.
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Polycarbonate
- These lenses are made of special polymer.
- This material is also called as 'bullet proof' material and is 10 times tougher than ordinary plastic lens.
- Thin and light weight - High refractive index (1.586)
- 100% in-built UV protection.
- Hence, recommended material for children and sports.
- Best lenses for rimless spectacles.
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