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Glasses Lenses

Eyeglasses - Single Vision LensesAt 512 Eye, we have the latest lens technologies available to ensure you get the perfect pair of glasses. There are so many types of lenses and options available, it can be a bit overwhelming. Below you will find information on common lens options.

Single Vision Lenses

Single Vision lenses allow for clear vision at a single distance (distance, near, or intermediate ranges). Patients under forty can use single vision lenses to see clearly at any distance. For individuals in their forties and older, they will need bifocal, trifocal, or progressive lenses to see multiple distances clearly. This is due to aging changes of the eye.

Multifocal Lenses

Progressive Lenses

Progressive LensesProgressive lenses are designed with distance vision at the top of the lens. The near, or reading power progressively increases the farther down the lens you look. The very bottom of the lens offers clear vision at arm’s length, whereas the middle of the lens is clear at intermediate distances. There are an infinite number of distances that can be seen clearly through a progressive lens, depending on which part of the lens you look through.

This is very convenient for most patients, as other multifocal lenses are more limited (patients can only see 2 distances clearly vs an infinite number). The only drawback is that progressive lenses have slight distortion in the periphery, and they can take a while to adapt to for new wearers. Most patients manage to adapt quite well, and prefer the advantages of progressive lenses to other multifocal lenses. Aesthetically, progressive lenses are superior to other multifocal lenses as they have no lines and look identical to a single vision lenses.

Lined Bifocal Lenses

Bifocal Lenses were invented by Benjamin Franklin in 1874, and are still widely used over 100 years later. A Bifocal lens is a lens that consists of two powers. In most cases, there is a distance prescription in the top portion of the lenses, followed by a demarcated line. Beneath this line on the bottom portion of the glasses is a prescription for reading. This allows the user to view both distance and near clearly without switching between multiple glasses. Bifocals can be altered to provide intermediate vision for computer use as well. The drawback to bifocals is that they only correct vision at two distances, not the infinite number of distances that can be seen clearly with a progressive lens. The upside of bifocal glasses is that for the two distances that are clear, there is a relatively wide viewing area.

Lined Trifocal Lenses

Trifocal lenses are very like bifocal lenses, except there are two lines and three viewing distances included in the lenses. The top portion is typically a distance prescription, followed by a demarcated line. Below this line is a small area of the lens with an intermediate distance prescription, followed by another line and a reading prescription at the very bottom of the lenses. Trifocals work well, but by adding intermediate vision to the lens, the reading area of the lens becomes smaller than a bifocal. Many patients prefer the aesthetics of a progressive lens which has no visible lines to a trifocal’s two lines.

Computer Lenses

We can customize a pair of computer lenses designed specifically for the distance you sit from your computer screen. Computer glasses can be single vision or multifocal, depending on your individual needs. Antireflective coatings can be added to decrease screen glare.

Lens Materials

  • CR-39 is a standard plastic lens material. This material works well for individuals with mild to moderate prescriptions who don’t require extra eye protection.
  • Hi- Index is a thinner lighter weight material than CR-39. Hi-index material is used for individuals with larger prescriptions.
    Polycarbonate is a shatter resistant material. This material is recommended for children and individuals wanting a superior level of eye protection. It is also used in sports and safety glasses.
  • Trivex is a shatter resistant material that offers slightly superior optics to polycarbonate. Like polycarbonate, it is also used in sports and safety goggles. Trivex is more expensive than polycarbonate, so for this reason polycarbonate tends to be more popular.

Anti-Reflective Lenses

Antireflective Coatings

Antireflective coatings help prevent glare from computer monitors, cell phones, and oncoming headlights from traffic at night. There are a myriad of options when it comes to antireflective coatings. Lower end coatings may smudge or form a cracked rainbow tint on glasses, making them almost unwearable. Higher end antireflective coatings offer much better quality, are more smudge resistant, and do not crack when exposed to heat. Antireflective lenses also look better aesthetically, as during interactions people will see your eyes, rather than reflections in the lenses.

Blue Protect

Blue Protect is a type of antireflective coating that specifically blocks blue/violet light from TV’s, computer monitors, tablets, cell phones, and other electronic devices. Earlier scientific studies showed that blue light may increase the risk of eye diseases such as macular degeneration. Later studies have disputed this finding. The jury is still out on whether blue light is dangerous in the long term, but in the short term it has been proven to disrupt REM sleep patterns, especially if you are looking at electronic devices shortly before going to bed. Blue Protect antireflective lens coating improves comfort and eye fatigue while using electronics. We recommend Blue Protect to patients who spend large amounts of time using electronic devices, or those who feel they may be experiencing poor sleep related to electronic device use.

Free Form Lenses a.k.a. Digital Lenses

Have you ever received a new pair of glasses only to feel like the lenses were clear, but not quite right? Higher order aberrations in the eye aren’t corrected by standard lenses. If present, these aberrations lead to vision that feels slightly distorted. Unlike standard lenses, free form lenses (also known as digital lenses) can correct some higher order aberrations. The front facing side of the lens is surfaced with precise computer controlled equipment. This modern surfacing process reduces aberrations, leading to crisper vision for many patients when compared to standard lenses. Digital lenses are available in both single vision and progressive lens designs.

Scratch Resistant Coating

Scratch resistant coating is a clear coating applied to the front surface of lenses that hardens the front surface of the lens, making the lenses more resistant to scratches. This is beneficial for individuals who tend to be rough with their glasses, as lenses are less likely to scratch if dropped or cleaned improperly. Scratch resistant coating is highly recommended for children.
Transision Lenses


Transition lenses turn dark when exposed to sunlight and are clear when inside. These are great for patients who don’t want to fully invest in an additional pair of sunglasses. They are available in both grey and brown and work very well outdoors. Transition lenses do not get as dark as traditional sunglasses when in a vehicle, as there is a U.V. protectant on most windshields that prevents the transitions from fully darkening. For this reason, some patients prefer traditional sunglasses. Other patients appreciate the convenience of having both clear lenses and sun protection in one pair of glasses.


At 512 Eye, we carry a large selection of both non-prescription and prescription sunglasses. Prescription sunglasses can be customized to your preference. We have a wide variety of tinting color options—from traditional browns and greys to mirrored lenses in red, blue, and other hues. Polarized lenses improve vision for certain activities by decreasing glare from flat surfaces. We also carry Oakley Prizm lenses. Oakey Prizm lenses are designed with customized tints to increase contrast for various activities. There are Prizm lenses specific to golf, fishing, cycling, and other activities. For instance, Prizm lenses can improve your golf game by making it much easier to see the golf ball on the green.
Sunglasses Lenses
If you are still unsure what lens type or coatings are right for you, come see us at 512 Eye. We pride ourselves in carrying high quality lenses. We have knowledgeable staff who can answer any of your questions, and have samples of various lens coatings you can see first-hand to make a more informed decision.