What are the disadvantages of high index lens glasses?

[Amy]

My prescription is -0.75 sph and -0.50 sph. When I was getting my new glasses in the optical store, they didn't have any 1.5 index lenses in stock so they put 1.6 index lens in. But I think it is not as good as my other pair of 1.5 lenses.

[Analia]

As you say, your prescription is very low and you don't have to get 1.6 index lens and only 1.5 index lens is enough for your power. If the lens wasn't filled your right prescription, you may experience some vision problems then. Wearing the glasses lenses with a power higher than your prescription will cause vision distortion and you may see waves in the lenses. If they didn't have 1.5 index lenses in stock, you can go other optical stores to have a look.

[Aria]

High index lenses are made for people with strong prescription. For the same prescription lenses, the higher the index, the thinner and lighter the lenses are. So, they are the idea choices for people with strong prescription. However, That not means the higher the index of the lenses, the better the eyeglasses lenses. According to your prescription, you needn't use 1.6 index lens. Index 1.5 lenses are enough to give you thin eyeglasses lenses.