If you have a strong vision prescription and wear glasses with thick, heavy lenses, you may have had high index lenses recommended to you. But just what are high index lenses, and are they really better than traditional glasses? Here's everything you need to know about high index before you visit your optometrist for new eyewear.
What Are High Index Lenses?
High index lenses are special lenses made from plastics with a higher refractive index. Refractive index is the scientific term for change in the speed of light when it passes through a material like plastic. The high refractive index of high index lenses mean they're thinner and lighter than traditional lenses.
What's the Benefit of High Index Lenses?
Many people with strong prescriptions hate wearing the thick lenses they need to correct their vision. With high index lenses, this no longer has to be a problem. As high index lenses can be made so much thinner or lighter than their traditional counterparts, they can fit into any typical frame style and create a more stylish and attractive look. Those who hate the way thick lenses magnify their eyes and create a 'bug-eyed' look may prefer thin high index lenses, which are less likely to have this result. Even people who aren't fussed about their appearance will appreciate the increased comfort of less heavy lenses.
Are There Any Downsides?
Generally, high index lenses come with few problems. Some high index materials are more brittle than low index materials, which can make them more prone to scratching. As they have a higher refractive index, the lenses can also create more glare as they reflect more light than traditional glasses. Both these problems can be address with lens coatings -- an anti-scratch coating can help with brittleness, while anti-glare coatings will take care of light reflection. One of the biggest downsides of high index lenses is their cost. Unfortunately, the materials and manufacturing processes used in creating these lenses make them more expensive than traditional lenses. However, many wearers feel this is a small price to pay in exchange for the benefits of high index.
Bottom Line: Should You Get Them?
Whether you should buy high index lenses depends on three things: your prescription, your needs, and your budget. High index lenses aren't of much use to people with mild prescriptions as they don't perform their vision correction function any better than traditional lenses. However, if you have severe astigmatism, nearsightedness or farsightedness, you'll be able to see the benefits of having thinner and lighter glasses. Of course, if you have a strong prescription but you don't care about the look or comfort of your current glasses, you have no need to buy high index lenses. Finally, budget will always be a factor. Those who have low budgets and tend to need to replace their glasses often may prefer to opt for cheaper traditional lenses. However, if funds allow, you're likely to feel high index lenses are worth the cost.