What is the difference between an eyeglass and contact lens prescription?

It should be noted that a prescription issued by an optometrist for glasses is not the same as a prescription for contact lenses. The eyeglass prescription usually lacks the base curve (BC) required to purchase contact lenses. It is important for the contact lens to match the natural curvature of your eye in order to ensure eye health. If the eyeglass prescription has a negative sphere, then the contact lens prescription is usually weaker; if the eyeglass prescription has a positive sphere, the contact lens prescription is usually stronger. If you have never been prescribed contact lenses before, you should definitely book an eye examination to have them prescribed and to receive instructions on how to insert and care for them.