Sure it is a whole lot easier to purchase lenses online, but be careful who you purchase them from. Many companies have lowered their prices, because they are selling contacts without a hard copy of a prescription. This has created a huge problem. The web sites usually ask for a doctor's name, but many companies don't always call the doctor to verify that a prescription exists.
Another reason to be careful is that many cosmetic lenses are made purely to change the appearance of the eye color. These lenses are made in many florescent and dark colors, but they don't fully correct vision. Even though they do not correct vision, they are still considered prescription lenses under federal law.
A third reason to be careful is because it is extremely important that the lenses you wear fit you. Poorly fitting lenses can keep the cornea from getting oxygen. This can cause corneal abrasions, which leaves the eyes open to infections that can cause permanent vision loss.
Many doctors believe teenagers are at the highest risk for not paying attention to these problems. Doctors think this is because teenagers are more likely to buy lenses without a prescription, and more likely to wear their lenses too long without cleaning them. They also are known to exchange them with others. Many organizations concerned about these problems are trying to make a law that requires a hard copy of a prescription before contacts can be sold to anyone. Please don't purchase them illegally.