The most fundamental difference between these models and prescription reading spectacles is that they have the same prescription for each eye/lens, generally +1 - +3.Prescription reading glasses are customised to each individual and each eye, and often contain a different prescription for each. They can also correct astigmatism if required.

The “Ready Readers" are made in bulk and do tend to be very cheap. The manufacturing process means that the frame is made in one piece, and so cannot be reused or have the lenses changed if any difficulty occurs such as a crack in the lens or a change in prescription. Even the higher quality Ready Readers which may be made with metal frames do not have screws and so cannot be changed or easily adjusted.

Prescription glasses and frames can be reused if your prescription alters. The lenses are centred in front of your eyes with the PD (Pupillary Distance) , whereas RR are centred in the middle of your frame. Also prescription is by definition more accurate.