Anti-Reflective Coating / Anti-Glare Coating (AR Coating)
This coating eliminates glare from both the front and back surfaces of your eyeglass lenses. This helps you to see more clearly through the lenses, as you aren't looking through a bunch of reflections to see the world. Most Anti-Reflective Coatings also come with a scratch coating (many of which are warrantied for up to 2 years against scratches). Ask your optician for the best option for you!
Computer Lenses / Blue-Light Blocking Lenses
With all the LED screens and lights we are exposed to all day, every day, we are being exposed to vast amounts of high-energy blue light. Your computer, smart phone, flat screen TV, and even fluorescent lights emit a lot of blue light.
What's wrong with blue light? Well, nothing... in moderation! Blue light allows the world to be more colorful, and the scattering of blue light by the atmosphere is what makes the sky blue. Your body even uses blue light to help regulate the sleep-wake cycle.
But, unlike UV rays, your body doesn't have any natural defenses to overexposure to blue light. And too much blue light can lead to macular degeneration and eye strain. And exposure to significant amounts of blue light at night can disrupt your sleep, as it tricks the body into thinking that it is still daytime due to the amount of blue light present.
Due to these increasing problems related to overexposure to blue light, manufacturers have developed lenses that filter out percentages of blue light, or certain ranges of blue light frequencies. As noted above, a certain percentage of blue light is actually required for a solid sleep-wake cycle, and so you don't want a lens that blocks out all blue light.
A word of caution- there are a variety of styles of blue light blocking coatings available, some of which actually increase reflections, and may cause problems for sensitive wearers during high-contrast activities, such as driving at night and watching movies in dark rooms. Other varieties of these coatings don't have as "bright" of a surface, and so are better suited to full-time wear, rather than computer-only use.
Transitions Lenses
Transitions lenses darken when exposed to UV light. This is very handy for people who go from inside to outside frequently, people who don't like carrying multiple pairs of glasses around, and for children. They are available in 3 colors: Gray, Brown, and Graphite Green (a grey-green color resembling the G-15 tint frequently found on Ray Ban sunglasses). The only downside is that they don't darken in most cars (since most car windshields have a UV filter in place to protect the upholstery, and the lenses only darken upon exposure to UV rays).
A frequent concern people have when considering Transitions is that they think they might darken when exposed to bright indoor lighting, but this is not an issue. They will only darken with UV rays- the brightness of the light doesn't affect anything. This also explains why they still get dark outside on cloudy days- as you know, UV rays are still able to penetrate cloud-cover. Most people find that their lenses don't get fully darkened on cloudy days, so this is normally not a problem, but it is definitely something you should be aware of.
Note: "Photogrey" is the glass version of Transitions. We no longer carry Photogrey, as we ran into a significant number of problems with the lenses darkening consistently or appropriately for our patients, even after several attempts spanning multiple months. So, color-changing lenses are only available in plastic, polycarbonate, trivex, and high-index materials.
Scratch-Resistant Coating
You can add a scratch-resistant coating to many plastic lenses. Some lenses already have a scratch-resistant coating included in the manufacturing process, and some other upgrades, such as Anti-Reflective Coating also include a scratch resistant feature, so check with your optician to see if one would be necessary for your lenses.
Roll and Polish Edges
This is a nice upgrade to consider for individuals who have thicker lenses. Without this treatment, lenses are finished with a flat edge with a matte finish. When a lens is "rolled," the flat edge is rounded off, making it appear to be thinner. An "edge polish" changes the appearance of the lens edges from matte to shiny. This can elevate the appearance to something more refined and almost jewelry-like, especially when you select semi-rimless / "half"-frames, or completely rimless / no-frame styles.
Be aware, however, that polishing edges can allow more light to come inside the lenses, which, for sensitive wearers, can cause distracting glints of glare in a lens without an anti-reflective coating. So always be sure to add an AR coating if you have your lenses polished.
Tint
We offer a wide variety of tint options- so wide, in fact, that we can tint your lenses just about any color you'd like! We offer solid tints (all one color throughout the lens) and gradient tints (tints that fade from dark at the top of the lens to lighter or even clear at the bottom, or tints that fade from one color at the top of the lens to a different color at the bottom). We can tint your lenses light or dark, according to your preference. Ask your optician to show you the wide variety of color options available!
Polarized Lenses
Polarized lenses filter out light that is reflected off of surfaces, such as water, snow, car bumpers, windshields, and metallic surfaces, making them the superior choice for most sunglass wearers. They feel "darker" and generally more comfortable to wear than a tinted lens, due to the fact that they eliminate the glare and reflections.
You can tell if a lens is polarized by holding the pair of sunglasses level (like they would be when wearing them on your face), looking at something with glare reflections (like a car), and then rotating the lenses 90 degrees. You will see the image gradually become brighter, as the glare is able to enter the lens when it is at 90 degrees, and then darken back when you bring the frames back to level, allowing the filter to do its job again.
There are certain individuals who should not purchase polarized lenses, including pilots (as the polarized part of the lens makes digital readouts from computers and screens almost impossible to read). Other wearers find it distracting that many cars' back windows look odd, because the polarized part of the lens allows you to see the pressure-points in windshields (due to the way the change in curvature and pressure inside the tempered glass influences the way that light passes through it).
Mirror Coating
For the ultimate light-blocking sunglasses, consider adding a mirror coating to your lenses. Because of the manufacturing process of applying tint to your lenses, we only recommend that you use it on polarized lenses, as this process can change or lighten tinted lenses, creating results that are inconsistent and unpredictable.
Mirror coatings reflect much of the light that would have entered into your lenses, allowing them to feel darker and more comfortable. These are the kind of lenses that prevent people from seeing your eyes through your sunglasses (just ask poker players!). Individuals who spend a lot of time in high-glare situations, such as skiers, snowboarders, boaters, volleyball enthusiasts, etc. benefit the most from mirror coatings. They also have a really cool fashion sensibility that makes certain frames just "pop."
There are two types of mirror coating available at Cochrane Family Eyecare: Flash and Solid. A flash mirror coating has less mirror coating than a solid mirror coating, which makes it less dark (it allows a bit more light to pass through the lenses), but it also has less of that typical "mirrored" look that some people dislike, so it is a way to get many benefits of a mirror coating without the flashiness of a solid mirror coating. Solid mirrors are the darkest, as they block out the most light possible. They are also the most reflective.
Mirror coatings- both flash and solid- are available in a range of colors, including black, silver, gold, blue, red, orange / yellow, and green. Ask your optician to show you samples.