Removing Glare from Glasses on Photo

In my experience you will need extensive Cloning and Brushing in Photoshop to 'Paint in' the missing detail areas of the eyes under the glass. Or even copying one 'good' eye to another Ps layer, flipping it horizontal, and placing over the 'bad' eye.

The best answer is to avoid the problem altogether by positioning your lights so as not to cause the glare, before you hit the shutter button.

One 'shoot' technique is to take a second photo of the people- WITHOUT their glasses, and clone the 'good' eyes into the glasses frames that have the 'bad' glare.