Eyeglasses today are fashion accessories, as stylish as purses and belts. So don't fret if contact lenses bother your eyes. Instead, scope out the latest frames to give your face a fresh look.

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What Types of Lenses Are Available?

As technology advances, so do lenses. In the past, they were made exclusively of glass. Today, most are made of high-tech plastics. These new ones are lighter, don&#;t break as easily as glass, and can be treated with a filter to shield your eyes from damaging ultraviolet (UV) light.

The following lenses are lighter, thinner, and more scratch-resistant than glass or the older plastic types.

Polycarbonate. These impact-resistant lenses are a good choice if you play sports, work where your eyeglasses could easily get damaged, or have kids who are tough on their specs. They also have built-in UV protection.

Trivex. They&#;re made from a newer plastic that&#;s similar to polycarbonate lenses. They&#;re lightweight, thin, and impact-resistant. They may also correct vision better for some people.

High-index plastic. If you need a strong prescription, these lenses are lighter and thinner than the old-school super-thick ones you may have had in the past.

For more information, please visit Hongsheng.

Aspheric. These have various degrees of curvature. That means they can be thinner and flatter so you can use a much larger portion of the surface.

Photochromic. Sunlight changes these from clear to tinted. You may no longer need sunglasses, although they may not darken in your car if the windshield blocks UV rays. They can be either glass or plastic.

Polarized sunglasses. These lenses reduce glare from a surface like water, so they&#;re great for sports and driving. But they can make it hard to see the liquid crystal display on your car&#;s dashboard.

Your type of vision problem will determine the shape of your lens. You&#;ll need a concave lens (curves inward) if you&#;re nearsighted. A convex lens (curves outward) will help if you&#;re farsighted. If you have astigmatism, your cornea is shaped wrong, so your lenses may be more like a cylinder. Simply put, the lens is a tool you use to focus light onto your retina in the correct way.

Cylindrical Lenses

by Ariel Seafish
(Tulsa OK)

Q: Hi everyone,

Two years ago I had my eyes checked and these was the prescription with cylindrical lenses:

OD: (SPH /) (CYL+0.25) (Ax 70)
OS: (SPH +0.5) (CYL+0.5) (Ax 100)

I was not sure if the glasses were only for reading, for distance or for both. Moreover, for some reason the right eye gave me such a pain that I quit wearing them in less than 2 weeks.

Yesterday I visited an eye doctor again and got this prescription:

OD: (SPH +0.75) (CYL 0.5) (Ax 150)
OS: (SPH +1.00) (CYL /) (Ax /)

The doctor said that I should wear them all the time. He said that I have problems reading because I actually have problems with distance vision. Fair enough, I do have some problems reading the street signs especially during the night.

What is unclear to me are the following:

1. Can a person have eyeglasses with "+" for distance?
2. Can someone goes from cylinder (OS: +0.5) to no cylinder (OS) and from Ax 70 (OD) to Ax 150 (OD)?
3. Can the spheres grow in 2 years from none to 0.75?
4. Wearing eyeglasses if you actually do not need them can impair your vision for good?

Thank you.
Ariel


A: Hello Ariel

What I can tell you from the beginning is that the two prescriptions you have with cylindrical lenses are written in two different ways.

The first is with (+) cylinder and the second with (-) cylinder this is why they look different. If we put them both with (+) cylinder, then the second will look like this:

OD: (sph +0.25) ( cyl +0.50) (ax 60)

So the difference between the first and the second prescription is small.

Now to answer your questions:

1. Yes, you can have (+) for distance view and is called Hyperopia, commonly known as being farsighted.

2. No, presence of cylinder means you have astigmatism, an eye condition that does not disappear, but normally, if the cylinder is not more than 1 diopter (0.25; 0.50), the correction is not mandatory, you will get a correction for it only if improves your vision. I see that first time you had it, but as you said you had a pain in the right eye wearing this glasses, the doctor was thinking that maybe this cylinder is to blame so next time he didn't put it there.

3. Yes, it can grow that much. It depends on how tired you'r eyes are, how much you are reading or working on computers on daily bases and if you wear a hyperopia correction or not. All this factors together can damage your vision over time.

4. If the diopters in these eyeglasses are big and you don't need them, they can do damage. Usually, you feel dizzy, have blurred vision or headaches, so you are not able to wear them anyways. If the diopters are rather small, like in your case, wearing them only get you more tired eyes, no permanent damage.

Arpi

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