Contact lenses have a variety of different brands and types, the specific choice of which should be based on the eye table, specific degree, astigmatism and other information for analysis, to choose the right contact lenses.
The condition of the eye surface is the key to whether or not to wear contact lenses.If you have ocular surface disease, it is not suitable to wear contact lenses, the cornea and lens contact process will be friction, may aggravate the disease.And the crowd with less tear secretion, it is more suitable for the contact lenses with low water content and high oxygen permeability, because the lens with high water content has strong water absorption, will in turn absorb a lot of tears, aggravating eye dryness.
Choosing a contact lens also involves in converting degrees.The degree conversion between glasses and contact lenses has a complicated formula, simply speaking, generally less than 400 degrees do not need conversion, 500 degrees within the increase or decrease 25 degrees, 700 degrees within the increase or decrease 50 degrees and so on.As the degree may change, it is best to go to a professional eye hospital to measure the accurate degree, get a detailed professional prescription and then match the lens.
When matching lens, astigmatism also needs to be considered.The light astigmatism that does not affect visual object, below the circumstance that does not have accurate use an eye demand, can wear ordinary contact lens directly.If the astigmatism degree is more than 75 degrees, it may be manifested as blurring and double vision, etc. Improper correction will cause visual fatigue and headache, which will affect the quality of life. It is best to wear contact lenses with astigmatism correction effect.
There are many first-line contact lens brands, and the quality of the products of the big brands is relatively more guaranteed, but it is not the more expensive the better.Choose the contact lens that suits him has certain difficulty, had better go to ophthalmic hospital or regular optician shop to undertake an examination first before match lens accordingly.