If you find somebody saying that his or her prescription glasses are scratchproof, please don’t believe him or her. Mostly in these cases, it is only a marketing gimmick implemented by the company or the retail store.
However, one thing should be remembered that this coating would not protect the glasses from a scratch if the glasses fall on a hard surface, but they will surely minimize the small scratches that may occur in the daily use, so that your glasses remain clearer for longer. But it depends on how carefully they are used.
Usual price of such hard coating designer glasses by local reputed retailers ranges from $15 to $20, whereas, buy designer glasses frames online, you will get the same coating for free.