Spectacle glass for masks - has lens of divergent powder of refraction cemented or fused to another of convergent powder

摘要

The spectacle glass is made of, apart from the lens having low-refraction material, a second lens (6) which is connected to the first lens (4) and has convergent power of refraction, being made of material of higher refraction. The face (7) of the second lens is spherical or toric, depending on the sight defect of the user. The two lenses may be either cemented or fused to one another. Lens for correction of long or short sight can be used. The lens construction is for masks, e.g. diving masks.