Lenses

Lens Style

Thin eyeglasses are attractive; thick ones aren’t. Light eyeglasses are comfortable; heavy ones aren’t. So it’s no surprise that most of us want the thinnest, lightest eyeglasses possible. Most eyeglass wearers are nearsighted, and require the basic physical property of lenses with edges that are thicker than their centers. The stronger the prescription, the thicker the edges. Hi-index-Eyeglass lenses are able to correct vision because they bend light as it passes through the lens. The amount of light-bending (or refraction) that’s needed to provide good vision is determined by the eyeglass prescription provided by your eye doctor.

Because of the ability to bend light more efficiently, nearsighted lenses made of high-index materials have thinner edges than the same prescription made from conventional plastic materials of the same prescription power.Lighter, Thinner edges require less lens material, which reduces the overall weight of the lenses. Lenses made of high-index plastic are lighter than the same lenses made in conventional plastic, so they’re more comfortable to wear. High-index glass lenses also have thinner edges, but high-index glass is heavier than conventional glass, so there is not as much weight savings with glass as there is with plastic lenses.

Lightweight lenses are even more of a benefit for farsighted prescriptions, which can make conventional lenses very heavy. And most high-index lenses also have an aspheric design, which makes them flatter and reduces the magnified “bug-eye” look that conventional lenses cause in strong farsighted prescriptions.

How Do Polarized Lenses Work?

Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. This means that, instead of light being scattered in all directions in more usual ways, reflected light generally travels in a more horizontally oriented direction.This creates an annoying and sometimes dangerous intensity of light that we experience as glare.Polarized sunglasses cut glare and haze so your eyes are more comfortable and you can see better.

Polarized lenses contain a special filter that blocks this type of intense reflected light, reducing glare.

Though polarized sunglasses improve comfort and visibility, you will encounter some instances when these lenses may not be advisable. One example is downhill skiing, where you don’t want to block light reflecting off icy patches because this alerts skiers to hazards they are approaching.

In addition, polarized lenses may reduce the visibility of images produced by liquid crystal displays (LCDs) found on the dashboards of some cars or in other places such as the digital screens on automatic teller (bank) machines.

With polarized lenses, you also may be unable to see your cell phone or GPS device. Boaters and pilots also have reported similar problems when viewing LCD displays on instrument panels, which can be a crucial issue when it comes to making split-second decisions based strictly on information displayed on a panel.

However, for most other sports and activities, polarized sunglasses offer great advantages. And today, many polarized lenses are available in combination with other features that can enhance outdoor experiences.

Polarized bifocal sunglasses or progressive lenses are examples of options for the presbyope who also likes outdoor sports.
And polarized photochromic lenses, which change from dark outside to light inside, may be right for the light-sensitive person who frequently is in and out of the sun on any given day.

Whether you spend your time waterskiing or boating, in-line skating or mountain biking, driving or jogging, polarized sunglasses may be the right choice to help you enjoy your life outdoors.

Another beneficial lens treatment is an invisible dye that blocks ultraviolet (UV) light. Just as sunscreen keeps the sun’s UV rays from harming your skin, UV-protective treatments for eyeglass lenses block those same rays from damaging your eyes. Overexposure to ultraviolet light is thought to be a cause of cataracts, retinal damage and other eye problems.

Regular plastic eyeglass lenses block most UV light, but adding a UV-blocking dye boosts UV protection to 100 percent for added safety. Other eyeglass lens materials, including polycarbonate and most high-index plastics, have 100 percent UV protection built-in, so an extra lens treatment is not required for these lenses.

Photochromic lenses also block 100 percent of the sun’s UV rays without the need for an added UV lens treatment.
Photochromic lenses such as those made by Transitions Optical are clear (or nearly clear) indoors and darken automatically in response to sunlight outdoors. They also protect your eyes from 100 percent of the sun’s harmful ultraviolet radiation.

These features make photochromic lenses a great convenience, because they reduce your need to wear prescription sunglasses in most outdoor conditions.

Today’s photochromic lenses come in a wide variety of lens materials. So whether you prefer polycarbonate lenses, high-index lenses, or regular plastic or glass lenses, you typically will be able to purchase a photochromic version of your preferred lenses.

Adapting to Your Progressive Lenses

When you are fitted with your first pair of progressive lenses, you may need a short adaptation period typically lasting a few minutes to a few days.This progressive lens has a typical configuration of distance, intermediate and near zones.This is because blending lens powers in progressive lenses lets you see clearly at all distances, but also causes minor aberrations in the peripheral part of the lenses (see diagram).

If you glance to the far right or left, especially when looking down, you see through these peripheral zones of the lenses and your vision may be blurred slightly. Peripheral aberrations also may cause you to experience a sensation of “swim” when you make quick head movements.

Over the last several years, progressive lens designs have been improved continually to greatly reduce peripheral aberrations. Most first-time wearers notice no problems at all.

If you do have problems with blur or “swim,” you may need to — at first — make slight head movements to look more directly at objects. But eventually these problems caused by peripheral vision disappear as you adjust.

If you have a lot of hyperopia, adapting to progressive lenses may take a bit longer than if you are only mildly farsighted or are nearsighted. But with today’s lens designs, nearly everyone can wear progressive lenses successfully.

To make sure you get the best value in progressive lenses, talk to a professional optician, who will be able to recommend a customized progressive lens solution for your specific needs and give you helpful tips on adapting to and caring for your new lenses.

Care For Your Contact Lenses

Do’s

• Wash and rinse your hands before you handle your lens. Clean, rinse, and disinfect your lens each time you remove them.
• Handle your lens with your fingertips, avoiding any contact with your fingernails.
• Apply hair spray before inserting your lens. Apply make-up after inserting your lens.
• Store lens in a leak-proof lens case when they are not being worn, and disinfect before use.
• Clean and disinfect one lens at a time to avoid mixing up the left and right lens.
• Use a lens case that clearly indicates left and right.
• Replace your lens and your lens case on a regular basis – visit your eye practitioner to discuss the most suitable lens replacement schedule for you.
• Keep the caps of your solutions closed when not in use.
• Use solution before expiration date marked on bottle.
• Schedule yearly appointments with your eye care practitioner.

Don’ts

• Do not re-use any lens care solutions.
• Do not use saline to disinfect your lens.
• Do not use eye drops or solutions not intended for use with contact lenses.
• Do not mix any eye medication with lens care solutions except under medical supervision.
• Do not use eye make-up in the inner margin of the eyelids as small particles could be transferred onto the surface of your lens.