Once your optometrist has prescribed what eyeglass lenses you need to get, there are various treatments and coatings that can improve the performance and longevity of your prescription lenses. The following are details of these treatments; talk to your optometrist about which ones you may need.
AR-Coating or anti-glare coating is a microscopic film made of several layers. It is placed on lenses and eliminates light reflections on the front and back surface of the eyeglasses. This enables more light to pass through the lens into the eye, improving vision.
AR-coated glasses are especially useful for those using high-index and polycarbonate prescription lenses, since the level of reflection increases with the refractive index of the lens material. In addition, AR-coated glasses are indicated for those with aspheric lenses, since they are flatter and reflect more light.
Every AR-coating manufacturer uses their own patented formula, but typically, all coatings are made of several microscopic layers of metal oxides placed in alternating order between high and low refractive index materials. Each layer targets a specific wavelength of light, so the higher the number of layers, the better its anti-glare properties.
Your optometrist may suggest a particular brand of anti-glare coating depending on your lifestyle. For instance, people who work on computers most of the time may need coatings that remove blue light.
Scratch-resistant coating is a clear film that is applied to the back and front of your prescription lenses. This coating does not make the lens scratch-proof; that is impossible. Instead, it simply makes the lens harder to scratch, whether by dropping or on those odd occasions you need to wipe them and you have no microfiber cloth close by.
Scratch-resistant coating may be especially useful for children's eyeglasses since they are more prone to accidents. Most lenses today have inbuilt scratch-resistant coats, including polycarbonate, Trivex and high-index lenses. You can talk to your optometrist if you're in an environment that needs extra scratch protection. However, you should always have a microfiber cloth and protective case for your glasses, and only use the cleaning solution recommended for your prescription lenses.
Fogging is common, particularly when a person enters a warm room after being in the cold. It is a safety hazard, since you won't be able to see until the fog clears. This can be life-threatening if you're a first-respondent to emergency situations, e.g. police officers or firemen. You can prevent this by having a permanent coating applied to your glasses to prevent moisture condensation on the lens surface when transitioning from cold to warm surroundings.
The fog-free coat can be applied to lenses of any kind, and can be fitted in the optical lab prior to cutting for your frames.
Even without the treatment, your prescription lenses are designed to block out most of the harmful UV rays. However, you can enhance this to offer complete protection by getting your lenses UV-treated. This is done by applying an invisible dye that absorbs/reflects all UV light, which can cause retinal damage, cataract formation and other problems on continuous exposure.
However, some lenses have inbuilt complete UV-Light protection, such as most high-index plastic and polycarbonate lenses. You don't need any extra treatment for these.
For more information about your options for prescriptions lenses, contact a local optometrist.