CONVENTIONAL VERSUS FREEFORM LENS DESIGN
While conventional lenses offer acceptable performance for many patients, newer technology in lens manufacturing is available. Freeform lenses, also referred to as "digital designed lenses", offer several levels of personalization for patients and their lifestyles. Conventional lenses are manufactured using backside surfacing only, with a standard cut frontside. Freeform lenses are made using an integrated double surface technology. Magnification changes from distance to near are cut on the front of the lens and horizontal power changes are cut on the back of the lens. This insures optimal vision across the entire lens, not just the optical center, eliminating the distortion or loss of clarity patients notice away from the center in conventional lenses.
Freeform lenses are available in single vision, lined bifocal, and progressive lenses. Our optician can assist you in deciding which level of Freeform lenses would be best for you, your prescription, and your lifestyle.
No matter what type of lens material you use, all lenses benefit from an anti-reflective coating (AR or anti-glare). AR coatings are similar to the coatings found on microscopes and camera lenses. They consist of several layers of metal oxides applied to the front and back lens surfaces that together block reflected light. The result is that reflections and halos around lights will disappear, especially at night. Wearers using AR coatings have better night vision and reduced eye fatigue when viewing computer screens for long periods versus those using non-coated lenses. Eliminating reflections on the lenses will improve their cosmetic appearance as well, making them look thinner or non-existent. Reflections on the outside of the lens are especially annoying as they distort the view of your eyes from onlookers. When they are eliminated, your eyes are more visible, you look better and you make better eye contact with others. An AR coating on the inside of sunglasses prevents light reflecting up into your eyes when the sun is to the side or behind you. Some AR coatings even prevent water spots from forming or skin oils from smudging!
Transitions® lenses automatically darken in the sunlight and lighten indoors. They are tremendously popular due to their inherent practicality. Transitions lenses contain photochromic dyes which cause the lens to activate—or darken—when exposed to ultraviolet (UV) rays from sunlight. Therefore, they only darken when sunlight hits them, and do not darken indoors. As outdoor light conditions change, the level of darkness adjusts, creating just the right level of tint and allowing just the right amount of light to enter the eyes at any given time. When the UV light diminishes, the lenses fade back to clear. This action allows Transitions lenses to help protect your eyes from the light you can see—reducing glare, diminishing eye strain and fatigue and enabling you to distinguish contrast more easily. Whats more, Transitions lenses block 100% of eye-damaging UVA and UVB rays, the same as a quality pair of sunglasses.
THINNER & LIGHTER LENSES
Many people know there are various options to make their glasses "thinner and lighter". The two general options for accomplishing this are polycarbonate or high-index lens material. Aside from its thinner and lighter qualities, polycarbonate material is also the most impact-resistant lens material available, so it is an obvious recommendation for children. High-index lenses are as thin or thinner than polycarbonate material. The high-index lens may provide better optics, especially with increasing prescriptions, than a polycarbonate material. Both materials also have a scratch-resistance and UV coating built into the lens. AR coatings are very important for high-index lenses, as they tend to have more reflection issues than other conventional lens materials. The AR coating will make these lenses look even thinner!
For those requiring a multifocal lens (bifocal or trifocal), the main decision is whether to have a line or no-line. Depending upon your lifestyle, one type of multifocal lens may be a better option than another. A no-line bifocal has a designated area in the lower portion of the lens that gradually increases in magnification as you look down. In comparison, a lined bifocal has a clearly delineated section of the lower portion of the lens that is essentially uniform in magnification throughout.
Sometimes, wearers who do a large amount of computer work may discover that a lined or a no-lined bifocal does not work very comfortably. For these individuals an occupational lens, or a lens designed specifically for computer work, may be the best option. There are several occupational lenses available—ask about them when you are here.
Many wearers will initially undergo a short adaptation period of a few days with either type of bifocal, which mainly consists of learning how to use the lens effectively. If you are taking longer than this to adjust to the new lens, it may be a good idea to have the glasses adjusted again to ensure proper fit and placement of the bifocal.