It is clear that you can not independently determine their individual settings, picking up his lens. This can only be done physician professional. You need to see an ophthalmologist, that he has made the necessary measurements. The survey will be made very carefully: the doctor will determine the degree of visual impairment, a condition of the conjunctiva, cornea, and tear ducts. Doctor must take into account whether you have the experience of wearing contact lenses, as well as the mode of stress on your eyes, lifestyle and physical activity.
During a visit to the doctor, you can do a fitting recommended brand of lenses, only then will the prescription. Having it on hand, you can already make an order for a certain brand in the pharmacy or on the internet, without trying.
The selection of suitable lenses for your eyes - an individual process. Their color must be chosen, taking into account the natural eye color and shade of your skin, hair, and even the color and style of the clothes you wear. Trial fitting that you make an ophthalmologist, will allow you to accurately determine the physical parameters and color lenses and avoid mistakes in the future with their purchase. Recipe that will write you a doctor, will not be valid always - your vision may change over time. Therefore, buying colored lenses without trying, you must guide the prescription of not less than six months before the purchase.