dial vision glassesreading glasses must be rugged. Presbyopia is near glasses, presbyopia with the eye is in the reading distance from the 40-year-old (+ 1.00D, that is 100 degrees), every 5 years to be added +050D (ie 50 degrees). But also in the use of the process of picking the frequency of several times the myopia, so reading glasses parts must be strong or high elastic material. Electroplating anti-scratch performance must be highlighted, the lens of the hardening process is better, in general to ensure that the use of 2 years is not serious changes, not rust, not serious flowers. In fact, at this point on a good reading glasses requirements are higher than the same grade with the glasses with frames.
Select lenses, dial vision glasses price is cheap on e-bey or website.in general, glasses lenses can be divided into two categories, namely, glass lenses and optical resin lenses.Glass lenses include optical glass lenses and high refractive index lenses (commonly known as ultra-thin film), its high hardness, good wear resistance, the general quality and the parameters will not change with time, but the glass lens anti Impact and weight to slightly less than the resin lens.
Resin lenses are generally much lighter than glass lenses, and the impact resistance is better than glass, but its surface hardness is low, more easily bruised. Resin lenses and coated lenses because of its characteristics are softer, so usually should not be careful not to let the mirror direct contact with hard objects, scrubbing is best to use water (or mixed with a small amount of detergent) cleaning, and then use a special test cloth or high-quality cotton Drain the water droplets on the glasses. In addition, the poor environmental conditions should be used with caution coated lenses, so as not to stain stains difficult to clean.