Read this before you buy contact lenses online:
The US FDA regulates contact lenses as medical devices, so there are strict rules about how they can be dispensed. Anyone looking to buy contact lenses online must have a valid prescription from an eye doctor. This means the prescription cannot be expired. This is for the protection of your vision and the health of your eyes. Reputable online retailers will not allow you to buy contact lenses online from their Web site without a valid Rx. Some online retailers ask you to fill in a form with your prescription and the name and location of your eye doctor, so they can verify your prescription before you buy contact lenses online. This is an acceptable and legal way for them to comply with the law.
Most contact lens prescriptions are valid for one to two years. Once the prescription has expired, you will need to see your eye doctor for an examination. Of course, you should make an appointment sooner if your vision changes or if your eyes become red, itchy or dry. Trauma to your eye, sudden loss of vision, severe pain or flashes of light requires a trip to the emergency room.