Technically speaking, you don't. The receptors used in photofocus are acute enough to pick up whatever you're PRing. Whether you actually wear glasses during the PR stage is purely a matter of preference. Personally, I don't.
If you don't need them for anything but reading you probably can get by withour glasses. Some people find that their vision improves as a result of photoreading. On the whole it's your call. There are a number of factors that makes it difficult to prescribe whether or not you should be using your glasses. The quickest way to find out is experiement.
I was wondering if you are supposed to wear glasses while reading do you need to wear them to photoread? Thanks!