When it comes to choosing bifocals or progressive lenses for your frames, it’s good to know the long and short of it before deciding which is right for you.

Possibly the most important part of the eyewear buying process is choosing the right glasses lenses. The quality of your lenses, their attributes and their coatings all contribute to how happy you are with your eyeglasses. There are so many options available on the market today, so it can be difficult to decide which type of eyeglass lens is best for you and your unique lifestyle.

Back in the day, people used to lovingly refer to strong eyeglasses prescriptions as “Coke-bottle glasses.” Translated, this means “thick lens glasses.” But with the advent of technological advances in eyewear, even those who need a strong prescription can have sleeker and slimmer lenses. The secret is high-index lenses.

Most glasses are made of plastic lenses, or “organic glass” if you want to get fancy. So why are glasses lenses made of plastic? In most cases, they’re lighter than traditional glass lenses used in eyeglasses, which means they’re more comfortable to wear. It’s also easier to apply lens coatings like anti-glare to plastic lenses. And there’s a reason children’s cups are made of plastic: it’s more resistant to impact. There are four main types of plastics used to make eyeglass and sunglass lenses: plastic, Trivex, polycarbonate, and high-index plastics.

A good pair of sunglasses does more than just protect your eyes from UV rays. Your choice in lens color also determines the color contrast that you’ll be experiencing. It might seem like a subtle decision, but choosing what color your lens is can make a huge impact on your daily life. Believe it or not, sunglass lens colors all have their own special application. Learning which colors are meant for your unique lifestyle can be a great first step towards looking stylish AND improving your performance in daily life.