What are prescription lens made of?

Before, opticians relied on separate optical laboratories to create eyeglass lenses. Today, there are numerous of full-service optical outlets that produce lenses for customers on-site. However, optical outlets do receive lens “blanks”—plastic pieces already formed to close-to-exact size with different curves ground into the front of the lens—from optical laboratories. Blanks with different curves are used for specific optical prescriptions. The type of lenses in your glasses play a big role in your vision, comfort and safety when wearing eyeglasses. And buying

You can observe in the non-bolded prescription that there is a plus (+) sign in front of the cylinder number. In case you are ordering a custom made prescription lens, you certainly do not need to worry about this. Lens comparison as viewed via an illuminated polarized lens. Notice the internal stress and distortion in polycarbonate lenses. Polarized lenses can be extremely helpful for people who work outside. For example, this kind of lens is often used by fishermen who work in bright light that’s being reflected off the water.

The Manufacturing Process

A progressive lens design is like a bi- or tri-focal lens in that it corrects more than one vision problem at a time. However, these lenses have no visible lines, improving the cosmetic appearance of your lenses while providing clear natural vision at all distances. At Eyeglasses.com, we only use labs that hire a large staff of experienced technicians, performing a large level of lenses every day. We do none our own edging services ourselves – everything is performed by our lens laboratories. The majority of our orders require stock lenses; our custom surfacing work is done by lens laboratories.

• If the frame is rimless, a groove is cut across the edge of the lens
• It can also be found in conjunction to high-index lenses to help expand cut down the visible thickness of the lens.
• lenses, which have a small plus segment, might help a farsighted person read or do close work, such as sewing.

Since glass is really a hard, non-absorbent material, applying a tint is difficult and is generally not recommended. 4 Next, the technician places each blank right into a generator, a grinding machine that is set for the optical prescription. The generator grinds the appropriate optical curves in to the back of each lens.

Scratch Resistant Coatings

Glass is harder than plastic, so glass lenses do not scratch as easily. However, despite the exceptional optics, glass lenses are heavy and may break easily, that may be a safety hazard. The weight of glass lenses can get uncomfortable, especially if you plan to wear them all day long.

Also, because glass is a much harder material than plastic, glass lenses usually do not scratch as easily as plastic lenses, even though they will have scratch resistant coating. All lightweight eyeglass lens materials have surfaces which are significantly softer and more prone to scratches and abrasions than glass lenses.

Using computer settings dictated by your doctor’s prescription, the technician creates very precise curvatures and the required thickness.