|
|
Are All lenses Equal? The Answer is No.
Just like photography,
optics counts. There is a difference between the inexpensive throw-away
cameras and a fine Nikon or Zeiss camera. Good cameras use good
optics. Good optics improves vision and comfort. Poor quality lenses may
cause noticeable
distortion, i.e. colored fringes and Remember, there is no clothing or item that you will wear or use more than your glasses. Not only does the quality have to be right, but the craftsmanship needs to be precise. Measurement, measurement, measurement. Frames need to fit your face besides being cosmetically appealing. Lenses need to be centered in front of your eyes both horizontally and vertically. Prescription specifications need to be taken into account upon picking lenses and frames. For example, large frames should never be used for strong prescriptions. Progressive lenses have the greatest variability in design and function. Newer better designed progressives have less distortion in the periphery of the distance portion and a wider reading channel. Different progressive designs work better under different conditions. We will match the progressive design to the way you function. Occupational progressives provide a wider intermediate area (computer viewing) and reading area. Some occupational progressives allow you to walk with them and others have larger reading areas. We will determine the best progressive design for you. Why Shouldn't You Get Cheaper Glasses?Better quality lenses provide better and more comfortable vision. Better quality frames hold their shape better; needing less adjustment. Better quality frames have thick alloy coatings which do not wear out or chip off. Remember, the first thing people see is your glasses. Not only do they provide you with good vision but they are a fashion item, that most people wear every day. When compared to clothing which is not worn every day, glasses are an excellent value. Many Opticians which seem to be cheaper are really more expensive. What About Lens Coatings?Every lens used out-doors must have a ultra-violet (UV) coating. UV light is thought to contribute to the development of cataracts and macular degeneration. Harmful UV light is present even on cloudy days. UV is more dangerous today than previous generations because: we no longer live in the shaded woods - we are directly exposed to the UV light; we have reduced the natures filter of UV light - the ozone layer; we are out doors more often; and we are living longer. Reading glasses do not need a UV coating. It is a myth that computer terminals emit dangerous UV light or that they can cause cataracts. Thus, your reading glasses do not need UV coatings. Anti-reflective coatings
reduce glare. We use the latest anti-reflective technology. We most
commonly recommend Zeiss anti-reflective Scratch resistant coatings are clear coatings that when placed on the surface of a plastic lens hardens to provide a durable, tougher lens. Coated lenses should last longer. Keep in mind that scratch resistance does not mean scratch proof. How Should I Care For My Glasses? This varies depending on the frame and lens material. Follow these instructions of do’s and don’ts. · Do clean your glasses with a mild dishwashing detergent or liquid soap. For best results let the glasses naturally drip dry. · Do use a soft paper towel to dry the glasses off. · Do use Zeiss spray cleaners or cleaning cloths to clean your lenses. (Available at the office) · Don’t use cleaning agents that contain ammonia or cream. They can ruin the coating on the your glasses. · Don’t use tissue to clean anti-reflective coatings. Anti-reflective coatings tend to attract particles and tissues contain a great deal of lint that tends to stick to your lenses. · Don’t use alcohol to clean your glasses. Alcohol can damage your frame and/or lenses the frame appear dry and brittle. · Don’t use your towel or tee shirts to clean your glasses since they may be abrasive to your lenses. · Don’t use crazy glue to repair your glasses. · Do use clear nail polish on the screws so that they won't come out. I Have Told I Need a Prism. What is a Prism? Prisms bend light. As a matter of fact all lenses that bend light have prismatic characteristics. If you do not have a muscle balance lenses should be made so that they center in front of the eyes. Inappropriately aligned glasses create unwanted prism with resultant eye-strain. Sometimes we purposely misalign the lenses to create prism. Prism can also be ground into the prescription, created by purposeful mis-alignment, and/or applied temporarily with a plastic paste-on prism. Generally, the purpose of prism is to eliminate double vision (diplopia), a muscle imbalance, or eyestrain. Our office receives patients and referrals from all over the world for the measurement and prescription of necessary prism to eliminate strabismus, double vision, and/or eye strain. What Do We Look for in Properly Made Glasses?
Why are There So Many Different Materials That Lenses are Made Of?Different materials have advantages and disadvantages. Listed below are the common materials. CR-39 - standard plastic, excellent optics, good for small and medium prescriptions Polycarbonate - safest lens, thin design, light and most shatter
proof. Disadvantage: color fringe with peripheral distortion in the higher prescriptions.
Newer designs have eliminated distortion. Excellent for sports, children eyewear and the latest rimless designs. High index plastic: available in a wide range of thinnest (1.60, 1.66, 1.67, 1.71, 1.74). High index lenses are thinner than a polycarbonate lens, and are available with scratch resistant/ Anti-reflective coatings. The optics are excellent and the lenses are designed for individuals with high prescriptions. Often prescribed in an aspheric design to improve optics and thickness. Crown glass - best optics and scratch resistant, but heavy and not safe, therefore, not used very much High index glass - thinnest lenses in excellent optics, but heavy and not safe Photo chromic- lenses that darken outside and lighten inside.
Photo chromatic
Polarization - the ideal sunglass lens for individuals with light sensitivity. These lenses provide excellent clarity in various weather conditions and maximize visual acuity by minimizing glare. Polarized lenses are prescribed as either clips-on or bonded within a lens reduce glare. Polarize brown tints are recommended for individuals who drive a great deal. It improves visual acuity, especially in dim weather conditions. I
|