Frequently asked questions.
FAQ'S ABOUT EVEWEAR and EYE-CARE
Q. What is the difference between bifocal, multifocal, and trifocal lenses?
A. Bifocals are lenses that have two parts - the upper part is used for distance vision, and the lower part is used for such close vision tasks as reading or sewing. Even though bifocal lenses can technically be considered a multifocal lens (because they have more than one focus), the term "multifocal" is generally used interchangeably with the term "trifocal", because they have three or more segments. In trifocals, the upper part helps view distant objects, the intermediate segment is effective for arms-length vision, and the lower section is for reading-distance vision,
Q. Are anti-reflective coatings really worth the added expense?
A. Many people who use lenses with an anti-reflective coating would wholeheartedly agree that they are worth every cent. Recent research showed that approximately 14% of all lenses sold in the U.S. have anti-reflective coatings. In Europe, however, more than 60% of all lenses are "A-R" coated. Anti-reflective lenses make use of metallic oxides that "coat" lens surfaces and help to reduce annoying reflections. A-R coatings also help to improve vision by reducing "ghost" images and light reflections that are both irritating and distracting. The "clear" appearance that A-R coatings give makes the process particularly popular among TV personalities. keep in mind however, that if you ask a former A-R user, they may warn you against the coating, which was once prone to crack and delaminate. But rest assured, newly developed techniques have dramatically improved the quality, reliability, and performance of A-R coatings.
Q. What does it mean if I have astigmatism?
A. In astigmatism, the eye's surface is shaped somewhat like a football (more oval), rather than like a baseball (round). Astigmatism causes the eye to focus on objects in two planes, only one of which is able to focus on the retina. In this case, out-of-round cylindrical lenses, opposite in design to those of the astigmatic eye, are prescribed to "neutralize" the defect.
Q. How safe is laser corrective surgery?
A. The procedure has proved quite safe thus far. There have been no reported cases of blindness in relation to either of the two most common procedures, PRK and LASIK. However, the FDA is aware of a few cases of severe eye injury requiring cornea transplant. Keep in mind that many patients may still require glasses to get to 20/20 vision. Everyone will also still require reading glasses when they reach the age of around 40 -45 years of age.
Q. How effective is laser eye surgery?
A. Most physicians agree that the treatment is generally effective. According to an article printed in the July-August '98 issue of the FDA Consumer Magazine, the treatment does seem to be permanent, although as people age and their eyes change, re-treatment may be necessary. It is also difficult to predict how your eyes will respond to the surgery, which means that you may still need corrective lenses for good vision, even after undergoing the procedure. In some cases, patients will need to undergo a second procedure. Unfortunately, some patients even find that after refractive surgery, their best obtainable vision with corrective lenses is worse than it was before being operated on. This can occur as a result of irregular tissue removal or the development of cornea haze. In others, the effect of the surgery can be gradually lost over several months. Again, re-treatment is an option.
"Halo Effect" is also a risk. The halo effect is noticed in dim light. As the pupil enlarges a second faded image is produced. For some patients who have undergone the PRK or LASIK procedures, this can interfere with night driving.
The FDA also reports that even when everything goes perfectly, there are effects that might cause some dissatisfaction. Older patients should be aware that they cannot have both good distance vision and good near vision in the same eye without corrective lenses.
Finally, if one eye is being treated at a time, the eyes may not work well together between treatments. If a contact lens won't be tolerated on the eye not yet operated on, work and driving can be difficult or even impossible.
Everyone will also still require reading glasses when they reach the age of around 40-45 years of age.
Q. What is the difference between an ophthalmologist, an optometrist, and an optician?
A. For this answer, we looked to Jeffrey Anshel, author of Smart Medicine for Your Eyes (Avery Publishing Group, 1999): There are three different kinds of professionals involved with the care of tile eyes, so it may not come as a surprise to you that there is some confusion over who does what. An ophthalmologist is a medical doctor (MD) who specializes in eye health and disease. After graduating from medical school, an ophthalmologist spends three more years learning about the diseases and surgeries of the eye (all ophthalmologists are surgeons). In order to become a board certified ophthalmologist, the ~'1D must pass a written and practical certifying examination in the specialty of ophthalmology. In telephone directories, ophthalmologists are listed under the general heading of "physicians". An optometrist is a doctor of optometry (OD). Optometrists are defined as healthcare professionals trained and state licensed to provide primary eyecare services. These services include; comprehensive eye health and vision examinations, diagnosis and treatment of eye diseases and vision disorders, detection of general health problems, the prescription of glasses and contact lenses, low vision rehabilitation, vision therapy and medication, the performance of certain surgical procedures, and the counseling of patients regarding their surgical alternatives and vision needs. Optometrists complete pre-professional undergraduate education at a college or university and four years of professional education at a college of optometry. Some optometrists also complete residencies. An optician is a technician trained to fill prescriptions for lenses written by optometrists and ophthalmologists. Opticians are trained to make glasses, fit eyeglass lenses into frames, and adjust frames to people's faces. In some states, they are also allowed to do fittings of contact lenses. Opticians generally have an associate college degree, which is awarded for completing a two-year undergraduate program.
Q. How does diabetes affect the eye?
A. Diabetes, a disease that prevents your body from making or using insulin to break down sugar III your bloodstream, can cause changes in nearsightedness, Farsightedness, and premature presbyopia. In fact, the early signs of diabetes are often detected during eye examinations. Diabetes can lead to cataracts, glaucoma, and decreased eye-muscle coordination and cornea sensitivity. Symptoms include fluctuating or blurred vision, occasional double vision, loss of visual field, or flashes and floaters within the eyes. However, the most serious diabetes-related eye problem is diabetic retinopathy.
Q. What is retinopathy?
A. Diabetic retinopathy is a weakening or a swelling of the tiny blood vessels in the retina of the eye, which can result in blood leakage, the growth of new blood vessels, as well as other changes. If left untreated, diabetic retinopathy can lead to blindness. Once damage has occurred, it is usually permanent, so it is important to control your diabetes as much as possible to reduce the risk of developing retinopathy. Frequent visits to your eyecare physician are also essential, since early detection is crucial.
Q. Do certain things put me at risk for developing retinopathy?
A. Several factors can increase the risk of developing retinopathy, including; smoking, high blood pressure, alcohol use, and pregnancy. (Source: http//www.virtualcity.com/dvc/cliabetes.lltml)
Q. What is presbyopia? And what causes it?
A. Presbyopia is a vision condition in which your eyes have difficulty focusing on close objects due to a loss of flexibility in the crystalline lens of the eye. Although our eyes stop growing at age 10, the lens continues to produce cells. Due to this growth, as well as the aging process, the lens can lose some of its elasticity and, therefore, its ability to Focus.
Q. At what age does presbyopia become a problem?
A. It's different for everyone. Actually, presbyopia doesn't have a sudden onset; it develops over a number or years. The condition will usually become noticeable in your mid-40s.
Q. What are the symptoms of presbyopia?
A. If your arms are too short to see reading materials anymore, that's a pretty good sign. At normal reading distance, you will notice blurred vision, while close work will fatigue your eyes and bring on a headache. An optometric examination that tests your near-vision ability can determine presbyopia. Once diagnosed, you will need glasses for reading or general close vision - although you may find that wearing your glasses all the time is best. Because the effects of presbyopia will continue to change through your 60s, periodic lens changes will
most likely be necessary.
Answers to the most commonly asked questions about
by Cheryl Coni, L.O., F.N.A.O.
After so many years in the optical business, an optician begins to anticipate many questions a patient may have before they are even asked. I hope I can answer a few YOU'VE been wondering about. So many choices are available today with new lenses being released to the public on a monthly and sometimes weekly basis. Plastic, Glass, Poly carbonate, Photochromatics, and the maze of information go on. There are so many issues to cover! "What is the safest lens for children and sports enthusiasts?" "How can I make my lenses thinner?" "These glasses are so heavy! They didn't seem heavy when I picked out the frame!" "The doctor says I should think about bifocals. " "I would love to have just one pair for outdoors AND indoors ... but glass is so heavy!" "My computer screen gives me a HEADACHE!"
Have you wondered about solutions to some of YOUR visual problems? An overwhelming majority of eyecare professionals strongly recommend Polycarbonate lenses for minors. The impact resistance of Poly carbonate is many times greater than glass and plastic, making glasses an ally in safety during play and activities. The natural ultraviolet inhibiting qualities reduce the cumulative damage of sunlight to the eye, and the scratch resistant coating that is always applied reduces scratching of the lens. Almost all prescriptions and lens styles are available in Polycarbonate, and it is the original thinner, lighter lens. The latest changes in the Polycarbonate lens are the flattening of the curves of the lenses and thinner center thicknesses for nearsighted eyeglass wearers. The flattening of the lens curve, called Asphericity, produces the thinnest, flattest lens with superior optics producing better "edge to edge" vision. These lenses can be used in farsighted, nearsighted, and bifocal prescriptions. Polycarbonate's unique impact resistance has allowed approval by the FDA for an unprecedented 1.0mm center thickness, and it is STILL far more impact resistant than plastic or glass! Polycarbonates have the lowest specific gravity of all lens materials . This means identical prescriptions in a Poly carbonate 1.0 center thickness will weigh approximately one half or less of the prescription made in regular plastic. (Plastic lenses weigh approximately half the weight of glass lenses. This may aid in determining how lightweight Polycarbonates really are.)
Plastic lenses have new qualities I should discuss, too. Photo chromatic lenses, the lenses that get dark in the sun, have previously been available only in glass and two years ago became available in plastic. However, the color and amount of sun and glare protection in plastic were inferior to the older and heavier glass lens. Recently, a vast improvement was made in these lenses. They now get dark faster than even glass photochromatics and have increased their ultraviolet light protection and depth of color. Plastic photochromatics have some advantages over glass photochromatics. They are light weight and the plastic photochromatics only darken in the presence of ultraviolet light. This may make a cosmetic difference in the appearance of photographs taken with bright lights or a flash. Ironically, this may also be a disadvantage while driving. Some windshields may inhibit ultraviolet rays due to the tinted window option purchased by car owners. New scratch coatings have also added to the longevity of the plastic lens, removing one of the main disadvantages of the plastic lens versus the glass lens. Plastic lenses are now available as highdensity (thinner) lenses as well as the regular versions, some with thinness factors rivaling Polycarbonates. Asphericity (flattening of the curve of the lens) is also available and produces the same effect as on Polycarbonate lenses. The high density plastics also have ultraviolet inhibiting qualities built in. Some controversy does exist as to distortion (real or imagined) in Poly carbonate lenses. However, foremost authorities, such as the Optical Laboratories Association of America and renowned optician Ralph Drew, find little or no difference and given the far superior impact resistance, choose Polycarbonates. Since the cost factor is greater in high density plastics, most consumers tend to agree.
Glass lenses have some new and exciting developments as well. Higher density glass (the highest density available) makes thinner lenses, but is not available in all prescription types. Some intermediate density lenses are available in photochromatics. The big disadvantage to glass always has been weight, and the thinner glass lenses continue to have the same problem. The impact resistance of glass is dependant upon chemical treating or heat treating the finished lens. This impact resistant quality is compromised when the lens has been scratched or chipped. Its biggest advantage has always been its scratch resistance quality and is still unsurpassed. The optical quality of glass is still preferred over other materials in the making of microscopes and other visually related scientific equipment, but the overwhelming majority of eyeglass wearers find plastics and Polycarbonates more than sufficient due to their other qualities.
Additional developments in coatings and treatments to all lens types are available in vast array! Anti-reflective coatings that are so helpful in night driving and computer operator situations have been improved by hydrophobic top coatings that function much like a hand rubbed wax job on your car to resist dirt buildup and make the lens far easier to clean than before. An added advantage to this coating is it's scratch resistance that is superior to most scratch coatings! The best news is that virtually all lens types and materials can be anti-reflective. No line bifocals have taken a leap forward in materials and designs making them available to even strong prescriptions that were previously left out in the world of non fashionable bifocal lines. Better design in no line bifocals make the transition to a new prescription easier and faster, while reducing the soft focus inherent in the outer edges of lesser quality no line bifocals. Even those of us who only need reading glasses can use this better design to be able to see from our nose to past our toes with special lenses, eliminating most of the off/on, off/on syndrome. These are but some new advances in lenses. I'd need a whole section of the paper to introduce them all to you! I do invite you to ask if you have some special question you'd like answered. I may not have the answer immediately, but I'll try to answer promptly and correctly as soon as I can! I can be reached at DIFFERENT FRAMES OF MIND ... an optical shop where the Focus is on YOU! at 397 East Central Street in Franklin, MA. You may call 508-520-6939. I'd be glad to help.
Cheryl Coni is the owner of Different Frames of Mind in Franklin and has had well over 40 years experience in the optical field. She is a Massachusetts Registered Optician, a Fellow of the National Academy of Opticianry, member of the Massachusetts Association of Registered Opticians, Certified Optician of the American Board of Opticianry, Certified Optician of Texas, Licensed Optician of Ohio, Member of the Better Vision Institute, and a member of the Women's Success Network.