Thursday, August 2, 2012

Buying eyeglasses should not be confusing...but it is!

Hello everyone,

When getting new eyeglasses, it can be daunting when trying to decide what kind of special tints and coatings you need on your eyeglass lenses. Also, picking out the frames can be an ordeal itself. (Do they look good? Do they fit good? Do you like them? Do I like them? What is the warranty? etc.)

So, I figured it would be a good idea to write an article so that anyone getting new eyeglasses can make an informed decision, which should make the whole process of buying new eyeglasses a little less stressful.

Single Vision Lenses and Bifocal Lenses:
The choice is a little easier if you need single vision lenses. Single vision lenses contain just one prescription in the lens, for near or for far. Typically, those patients under 40-years-old who have good focusing ability just need single vision lenses. However, for those with focusing problems, bifocal lenses are typically required.

If you are at the (dreaded) bifocal stage, the first choice is to decide between a bifocal and a trifocal option. A bifocal lens allows you to see at two separate points, far distance (driving, watching TV) and near (usually between 12 to 16 inches). A trifocal has a third section in the middle portion of the lens that allows a clearer view of an intermediate distance (between 2 to 3 feet) that is typically “washed-out” or blurred when trying to look through bifocals. The typical bifocal and trifocal are called “lined” bifocals or trifocals, because there is an actual line that is visible on the lens that separates the distance and near portions of the lens.

Lined Bifocals/Trifocals vs. No-line Progressive Lenses:
The next decision involves either choosing the “lined” bifocal/trifocal or going with a “no-line” progressive lenses. There are benefits to both types of lenses. With a line bifocal/trifocal, it is usually easier to switch between the reading and distance portion of the lens. The “lined” bifocals/trifocals are also usually less-expensive compared to the specialty design of progressive lenses and have a quicker adaptation period.

Progressive lenses are cosmetically appealing, because there are no lines visible on the lens. These types of lenses also provide the most complete range of vision, allowing you to see from far distance all of the way to your reading vision, depending on where you look through the lens. People typically had trouble adapting to the older styles of progressive lenses. However, progressive lens designs have gotten better over the last few years, causing less distortion and better adaptation.

After choosing the single vision lenses or bifocal type, there are different types of lens materials, coatings and tinting options. What you decide on depends on your lifestyle and the type of work and hobbies that you perform.

Plastic, Polycarbonate, Glasses and Hi-Index (ultra-thin) Lenses:
Most lens materials are made out of plastic, which is very safe, but not shatter-resistant. If you do a lot of work that requires a great deal of eye safety, polycarbonate is the most shatter-resistant material available. Children and those who are monocular should be in this material because it is the safest lens option.

Glass lenses are still available. It is usually more expensive than plastic and polycarbonate. However, plastic and polycarbonate are prescribed more because the optics are still excellent, and they are more light-weight and have a better safety profile.

A high index plastic lens is lightweight and thinner than all other lens materials. Individuals with a very high prescription always had to deal with thick lens edges in glasses that would weigh heavily on the bridge of the nose. The high index can be used for any prescription, but it is especially recommended for those individuals with high prescriptions to allow the glasses to be lighter and more cosmetically appealing.

Scratch Resistant Coatings:
If you use your glasses extensively, or tend to throw them around a bit, you may want to consider a scratch-resistant coating. This can be placed on any type of lens material, but is always recommended for polycarbonate, since it tends to scratch more easily than other materials. The coating adds a layer of warranty on your eyeglasses lenses. If you're hard on your eyeglasses, they will still probably scratch with or without the scratch resistant coating. However, the warranty usually allows the lenses to be remade (at little or no cost) if they get scratched from normal use. If you run over your glasses with your car and the asphalt demolishes your lenses, the warranty of "normal use" would not apply.

Anti-reflective (anti-glare) Coating:
I always recommend an anti-reflective coating, which is also called an anti-glare coating. This coating reduces reflections on the eyeglass lenses, and helps in a variety of ways. Primarily, the anti-reflective coating allows more natural light to enter your eyes, which in turn provides clearer vision. It reduces night-time glare from headlights or streetlamps, reduces eye fatigue from moderate reading or computer use, and can reduce light sensitivity during the day and at night. Some people refuse getting this because the coating “flaked-off” or “pealed-off” on a previous pair of eyeglasses. The new quality coatings do not tend to "flake" or "peal." However, let me point out that there are many different manufacturers of coatings, and therefore, different qualities of coatings. My practice typically uses the high end quality lenses and lens materials, versus optical labs with high volume or online resellers.

UV Coating:
If you are outdoors a lot, you may want an ultraviolet coating, or UV coating. The UV coating is a clear coating on the lens that protects your eyes while you are outside from harmful UV rays. UV can cause cancer of the skin around the eye and of the eye itself, as well as possibly promote the development of cataracts and macular degeneration.

Tints and Transition Lenses:
Tinting is also a great feature if you spend a lot of time outdoors or are a person who is light sensitive. There are solid tints that are same color throughout the whole lens and graded tints that are darker at the top and lighter at the bottom of the lens. There are also many different color options when prescribing a tint. Certain colors are preferable to specific activities, such as fishing, hunting and playing golf to enhance contrast and reduce glare. There are also lenses that darken when activated by sunlight. These types of lenses are called Transitions, or photograys. The older style of these lenses used to take a long while when changing from dark to light, but the newer technology allows this change to occur much faster. One thing to point out is that Transition lenses are activated by UV light. The car windshields and windows contain a UV blocking material, which is why Transition lenses don't get dark in the car unless you have a window rolled down or a moon-roof open. If you're looking for a darkened lens option for driving a car, polarized sunglasses would be the better option.

Polarized Lenses:

Polarized lenses reduce the amount of reflected glare off of surfaces, allowing for clearer vision and reduced light sensitivity. It is definitely recommended for boaters or fishermen to reduce the issues caused by the sun reflecting off of the water’s surface. However, polarized lenses also reduce glare for many other activities, such as driving, skiing, golfing, and running.

So, as you can see, the added features are very helpful in a variety of ways. Your eye doctor (hopefully, me!), along the help with the optical department, can assist you in selecting the special features that would aid you the most. As a new practice, I handle all of the measurements on the optical side of the practice as well, so you can be assured that I give you the proper recommendation and fitting when it comes to your new eyeglasses.
Take care,
Dr. Weaver