The Promate Scope Mask is ideal for medium faces which facial seal size Width 4-1/2 * Height 3-3/8. It features crystal, liquid silicone injected skirt and strap, double edge comfort seal, low volume. Plus, prescription (Rx) lens is available in our product line for this model. Rx lens will be installed in the mask by our trained techanician.
Corrective lens is designed for off-the-shelf correction. Lens is not for who has complicated vision problems such as astigmatism (correction needed for both near and far away) or multi-vision. Should you have other questions you may contact us.
The upper part of the biofocal lens is generally used for distance vision (NO PRESCRIPTION,) while the lower part is used for near vision with adjustment power for close-up work. A segment line separates the two section for bifocal lens type. By contrast, both farsightedness and nearsightedness are single vision which has the same optical focal point or correction over the entire area of the lens.
Tempered glass is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength. Tempering creates balanced internal stresses which cause the glass, when broken, to crumble into small granular chunks instead of splintering into jagged shards. The granular chunks are less likely to cause injury.