Lenses & Coatings
When light hits a standard lens, some of the light enters through to your eye and some bounces off the surface of the lens, resulting in glare. Most wearers notice this when driving at night or viewing computer screens. Anti-reflective lenses reduce glare and reflections by increasing light transmission through the lens. This allows more light to enter through the lens to your eye, which results in better vision and clearer lenses.
High Index Lenses
Years ago, the only materials available for use as lenses were glass and a hard resin called CR-39. More recently, high index lenses have become available. High index materials are named because they have a higher index of light refraction. As the index of refraction increases, the thickness and weight decrease. In other words, high index materials are thinner and lighter than your standard plastic lens. Options available in order of decreasing weight include polycarbonate, trivex, 1.60, 1.67, and 1.74. Talk with our trained options to decide which lens material is right for you.
Photochromics (Lenses darken with sunlight)
Photochromic lenses, also known as Transitions, darken when exposed to UV rays. When the wearer goes outside, the lenses darken or tint. When the wearer goes back inside, the lenses become clear again. Photochromic lenses are great for those with an outdoor lifestyle, although they do not replace the need for sunglasses completely. This is because they do not darken as fully when worn while driving a car since the windshield absorbs much of the UV light required to activate the lens. Nevertheless, photochromic lenses have improved greatly over the years and now can become much darker and clearer than ever before.
Glare from wet roads, light reflecting off other vehicles, and glare from your own windshield can be annoying and dangerous. Polarized lenses significantly reduce glare by blocking all horizontal light that enters through the lens. This is much healthier for your eyes than standard tinted sunglasses because it is literally cutting the amount of UV light entering through your lens in half, thus reducing the amount of light hitting your retinas. Your retinas need sun protection the same way your skin does and polarized lenses are a great way to protect your eyes. They also make a world of difference for any outdoor enthusiast. For example, fishermen can eliminate bright reflections from the water and actually see into the water more easily than with tinted sunglasses. In addition, drivers can enjoy the safety and comfort that polarized lenses provide while driving.
For many people, different lenses are needed for seeing at different distances. Bifocal lenses have two areas of focusing power within the lens. The top portion of the lens is used for focusing on distant objects, while the bottom portion of the lens is used for near viewing. One main drawback to bifocal lenses is the visible line. Fortunately, recent technologies have developed a new type of lens, called the no-line, or progressive, lens.
Trifocal lenses are similar to bifocals in that they have multiple prescriptions within the lens. Instead of having two areas of focusing power, trifocals have three, each separated from the other by a distinct line. The three windows allow for focusing on distant objects, intermediately distanced objects, and for reading. One advantage of this design is that the intermediate and near sections are wider than those of progressive lenses.
One of the main problems with bifocal and trifocal (multi-focal) lenses is that the lines separating the various focal ranges are visible to the wearer, and often cause images to “jump”. An improvement in multifocal design is the no-line or progressive lens. Progressive lenses provide a smooth transition from focusing on distant objects to nearby because they do not have a distinct line which separates the focusing powers. Instead, a gradual change in power allows the wearer to focus on objects at all distances. Distant objects are viewed through the upper portion of the lens, while near objects are viewed through the middle and lower portion of the lens. Progressive lenses are great for everyday wear and for those with specific work settings and hobbies.
Nowadays, there is a lens for just about everybody and sometimes your everyday lens may not be ideal for your occupation or hobby. Therefore, your optometrist may recommend multiple prescriptions for your various needs. For example, a specialty lens that is becoming increasingly useful is designed for computer users. Computer lenses have “windows” designed for viewing your computer screen, the keyboard, and near objects for reading. In addition to an office lens, there are various lenses for golfers, musicians, mechanics, and even cell phone users.