The properly fitted of contacts is important because of the way it works. The pair of lens usually placed on a layer of tears on the surface of your eye. There is no one-size-fits-all as the shape of the eye and size differ from person to person.  When you use contacts, it will float on your eyes so you hardly know you're using contacts. That can happen only if the fit is perfect. Also, you need some follow-up checks to make sure your eyes haven't changed.  You should check your eyes immediately, if you experience any kind of irritation or change in your vision. 

Experienced eye specialists provide you with the proper prescription after the checking and fitting is done. In a prescription you will find on how often contact lenses should be changed the prescriptions can last from one to two years. You will have to buy a new one when your prescription expires. 

It is strongly advisable to you to visit an optometrist before getting a pair of non-prescription contact lenses. He/She can measure your eyes and recommend the right size and type of lens for you. You can also get some advice on the correct care and maintenance of your lenses. Another advantage of visiting a doctor is that you get to try on samples of colored contacts in different shades and decide whether green, brown or blue contact lenses suits you the most.