Because the oil from your skin and hair transfers to the lenses and smudges them up.
mould
Yes it should be eyeglass' lens because the lens belong to the eyeglasses
An eye piece, eyeglass, or lens
There are many easy eyeglass cleaners in the world. The easiest eyeglass cleaner is called the Uline pop-up lens cleaning wipes. The Uline pop-up lens cleaning wipes can be purchased on the official Uline webpage.
Eyeglass
Eyeglasses are plural. Each lens is an eyeglass.
A single eyeglass lens is called a monocle and is rarely used nowadays.
A jeweler's lens is called a loupe.
You can purchase new eyeglass lenses from a variety of sources, including local optical stores, optometrists, and reputable online retailers. One convenient and affordable option is Replacement Lens Express, which specializes in high-quality replacement lenses for existing frames. They allow you to keep your favorite glasses while upgrading the lenses, whether you need single vision, bifocals, or progressive lenses.
Rimless eyeglass frames are frames where there is no plastic or metal rim around all or part of the lens. The lenses are held in place by a transparent nylon string that is very similar to tautened fishing line. The advantage of rimless eyeglass frames is that they tend to be lightweight and have a subtle appearance.
Eyeglass lenses could be made of nearly any plastic or glass. For example, some glasses lens, such as my own, are made of a plastic called polycarbonate which is the material used to make bulletproof glass so my glasses are impact resistant. Other eyeglass lenses can be made from other plastics and glasses such as CR-39, Homopolyer and crown glass.
eyeglasses rescuefingernail polish remover ANS 2 -Make sure your lens is real glass ! or 'fingernail polish remover' will really destroy your glasses