Some lenses doesn’t need a replacement until you consult a doctor but some need to be replaced after a short span of time. If you are buying contact lenses that are disposable in nature then it must be replaced after every two weeks so your eyes are safe and vision is strong as well. Optometrist check eye and suggest the proper contact lenses that fit properly.
The change in vision is one sign which states you need a lens replacement, but before you replace the lens make a visit to the doctor. They have to make sure that your eye doesn’t need new prescription or new lenses. Since the vision may change, a correction with the lenses optical is must.
Generally the lenses can be replace after one to two years, but if there are visionary problems which is making it difficult for you to view properly, then a replacement will be recommended by the doctor and buying contact lenses from a new company will be recommended.. Sometime, the eyes get well on their own and it could be one reason to feel the changes in vision. Thus, you may not need a heavy number for your lens.
After buying contact lenses you may feel some changes in your eyes. There are some people whose eyes produce certain lipids and proteins much more than that of others. Thus, a replacement is necessary more frequently with such people because their eye behaves differently.