There is a difference in the lense quality of glasses.The first one is glass which is the most scratch-resistant material but it is heavy and easy to break.The second is plastic which is lighter and hard to break.The third one is high index which is lighter and thinner.This kind of lens making eyeglasses more fashionable and comfortable.
Yes. There are several kinds of lens materials. One is glass lens which is the most scratch-resistant and provides the clearest vision. But it is the heaviest of all the lenses. The second one is plastic lens which is lighter and more shatter-resistant than glass. The third one is polycarbonate Lens which is also a light material. And it is more durable than plastic and glass. The last one is high index lens. If you have strong prescription, the high index will make your lens much thinner, lighter. But it is more expensive.
Yes, there is a difference in the lens quality of glasses. But I often choose plastic lenses for it is lighter and cheaper than other kind of glasses. It is said that plastic lenses are easy to get scratches on them. So I often have them coated with anti-reflective coatings. This kind of coating can prevent our eyes from the damage of the reflection and glare of the computer screens. And I often take good care of them to avoid being scratched. If there are some scratches on the surface of the lenses, I will buy the cleaner to remove the scratches. But the coating will be removed at the same time.
Well, the lenses made by different materials will charge you differently. Take a look at the prices and your can know what kind of lenses are better. But there are other things that a company may take into consideration when they are setting the prices. They are advertising fees, transportation fees, and even the brand of the glasses. Though I will not suggest you to buy a pair of Gucci glasses, I think you'd better buy a pair of glasses of good quality for good glasses will make you feel more comfortable.
Glass lenses can give you the clearest vision and is the most scratch-resistant. But glass lenses are the heaviest kind of lenses. Plastic Lenses are very light and they are more shatter-resistant when compared with glass lenses. Polycarbonate Lenses are the most shatter-resistant lenses and they are very light too. I strongly recommend children to choose this kind of lenses for they are less likely to break than plastic lenses or glass lenses. It is very safe but it will cost you more. And there is another kind of lenses that is called high-index lenses. if you have thick lenses already, you can try this kind of lenses for they are lighter and thinner compared with other lenses of the same degrees.
I think you'd better have a try before buying a pair of glasses. I have bought a pair of glasses in an optical shop. The boss of the shop told me that the lenses he recommended for me was the best kind. He also told me that he had coated my lenses already but later one of my friend who was working for an eyeglasses company told me that my glasses couldn't prevent reflections and glare of computer screens. There were no coatings! The boss lay to me. I hate that guy. So you'd better ask someone who can identify the materials of the lenses to help you. Good luck!