DeForrest Eye Center

 

What are High Index Lenses?

A high index lens is a lens that has a higher “index” of refraction. This means it has a greater ability to bend light rays to provide clear vision for people with stronger prescription glasses. But that’s the technical terminology. What do high index lenses mean for eyeglass wearers?

Thinner, lighter, and more visually appealing, that’s what! High index lenses are manufactured to be thinner at the edges of the lens and lighter in weight overall.

High index lenses are a good option for people who have strong prescriptions for myopia—commonly called “nearsightedness” due to a difficulty in focusing on far objects. A high-index lens can bend light rays more, while using less material in lenses created for both nearsighted and farsighted people (hyperopia).

No more soda bottle glasses

In times past, strong prescriptions meant thicker, heavier lenses, giving some a “glass bottle” appearance. But now, with high index glasses available in thinner, lightweight plastic (as well as slightly heavier glass), lens wearers with stronger prescriptions can get more attractive, yet equally effective, lens products. Because high-index lenses bend light more, anti-reflective (AR) treatment is often recommended as an add-on for optimum clarity of vision.

For better comfort, better vision and improved cosmetic appeal, people with strong prescriptions can’t beat high-index lenses.

 

Photochromic lens technology has been around for over 40 years. Photochromic lenses change from clear to dark based on the intensity of UV radiation. Remove the source of UV radiation from the lenses, and they return to their clear state.

The amount of photochromic reaction (how much a lens darkens) depends upon the intensity of the UV radiation present, combined to a lesser extent with the current temperature of the air. That means photochromics adjust automatically to indoor and outdoor light conditions. Photochromic lenses automatically adjust to outdoor lighting conditions by providing the right level of tint, and return automatically to their clear state; both indoors and at night.

Watch a short video on photochromic lenses:

 

Polycarbonate and Trivex lenses are special high index lenses that offer superior impact resistance. These lenses are up to 10 times more impact resistant than regular plastic lenses, making them an ideal choice for children’s eyewear, safety glasses, and for anyone with an active lifestyle who wants a thinner, lighter, safer lens.

Polycarbonate lenses have a refractive index of 1.59, making them 20% to 25% thinner than regular plastic lenses. They are also up to 30% lighter than regular plastic lenses, making them a good choice for anyone who is sensitive to the weight of eyeglasses on their nose.

Trivex lenses may be slightly thicker than polycarbonate lenses, but they provide comparable impact resistance and, like polycarbonate lenses, they block 100% of the sun’s harmful UV rays.

Source: Polycarbonate vs Trivex article by AllAboutVision.com ©2009 Access Media Group LLC. All rights reserved. Reproduction other than for one-time personal use is strictly prohibited.

 

 

Referred to as "no-line" bifocals or trifocals, progressive glasses are ideal for patients who have presbyopia —a vision condition marked by a decrease in the ability to focus sharply on nearby objects.

As we age naturally, our ability to see nearby objects and objects in the distance can decrease. Progressive lenses address separate visual needs in one lens—usually with a “distance viewing” field build into the upper portion of the lens, and a “near vision” field built into the lower portion.

Unlike traditional bifocals or trifocals, there are no visible lines separating the different fields of a progressive lens. Your eyes are seen clearly behind the progressive eyeglasses, you’ve got the same “look” as eyeglass wearers often half your age, and there are no “lens lines” to distract your vision.

Watch a short video about Progressive Lenses:

 

 

 

Special thanks to the EyeGlass Guide, for informational material that aided in the creation of this website. Visit the EyeGlass Guide today!

 

When it comes to prescription lens care, there’s a simple rule that, if followed, will virtually guarantee years of optimum performance from your glasses: If they’re not on your face, then keep your eyeglasses in a case.

Trouble is, no one really follows that simple rule, all of the time. (You know who you are.) If you, like so many of us, don’t always use a solid case to store your prescription glasses, then the following lens care and maintenance tips will go a long way toward maintaining your healthy sight.

Cleaning glasses and protecting your lenses

Keep it clean. Keep it simple. To wash your prescription eyeglass lenses, eye care professionals suggest you gently rub your lenses clean with your fingers using warm, soapy water. Rinse them, and then pat them dry with a clean, soft cloth. Many optical suppliers sell ultra-fine, machine-washable microfiber lens cleaning cloths that trap dirt and dust. Try to avoid rubbing prescription lenses with rags, facial tissues or paper towels, as they could scratch your lenses. And definitely avoid using household cleaners, acetone or soaps with cream—as chemicals may damage your frames.

A strong case for storage

Storing your lenses in a sturdy protective case whenever you are not wearing them will go a long way towards preventing scratches on your lenses. Proper storage also helps to keep prescription eyeglass lenses clean while protecting your valuable frames. Never place prescription glasses in a purse, pocket or bag unprotected.

Let them down gently

Okay. You don’t always use the case. If setting your prescription lenses on a table or desk, it’s best to close your frames first before laying them down. Always set them frame-side down to avoid scratching the lenses. The floor is never a good place to leave your glasses. And when in the bathroom, remember: A sink or vanity top puts your lenses in an unfavorable position. Spatters, sprays and cosmetic products can quickly soil lenses. What’s more, anti-reflective (AR) treatments can be damaged by hairsprays or perfume.

Keep glasses on your nose, not on your head. Prescription eyeglass lenses are designed to rest on your nose in front of your eyes; not on the top of your head. Frames can become misaligned in this manner, making even the cleanest of lenses less than effective if not positioned properly in front of the eye.

Special thanks to the EyeGlass Guide, for informational material that aided in the creation of this website. Visit the EyeGlass Guide today!

 

Finding eyeglasses with the qualities that are most important to you could be as simple as choosing a frame material, each distinguished by its own strengths.

You can also choose frames based on factors such as color, hypoallergenic materials, durability, lightness, price and uniqueness.

Metal frames

Metal is the most popular material for eyeglass frames. There are many types of metal you can choose, with each having its own distinctive properties.

Titanium.This premium metal is very strong, durable, corrosion-resistant, and is 40% lighter than other metals. It’s also hypoallergenic, making it a nearly perfect material for eyeglass frames. Titanium frames are available in several colors.

Beta titanium.This is an alloy of predominantly titanium, with small amounts of aluminum and vanadium. These other metals in the alloy make beta titanium more flexible than 100% titanium for easier fitting adjustments.

Memory metal.This is a titanium alloy composed of roughly 50% titanium and 50% nickel. Frames made of memory metal are extremely flexible, and can be twisted or bended to an extreme and still return to their original shape. This feature makes memory metal frames great for kids or anyone who is hard on their glasses.

Beryllium. This lower-cost alternative to titanium resists corrosion and tarnishing, making it an excellent choice for anyone with high skin acidity or who spends a good amount of time in or around salt water. It's also lightweight, strong, flexible and available in a wide range of colors.

Stainless steel.This is an iron-carbon alloy that also contains chromium. Stainless steel frames are lightweight, strong, durable, flexible and corrosion-resistant. They also can be produced in matte or polished finishes.

Monel.This popular, inexpensive material is an alloy of nickel and copper. It is less costly than other metals, but – depending on the quality of the plating used – Monel frames may or may not discolor and cause skin reactions over time.

Plastic frames

Zyl. This material (also called Zylonite or cellulose acetate) is a lightweight and relatively inexpensive type of plastic. It’s also the most popular plastic used for eyeglass frames. Zyl frames are available in a wide variety of colors, including multi-colored models and frames with different layers of color.

Propionate. This is a nylon-based plastic that is strong, flexible, lightweight and hypoallergenic. Propionate is often used in sports frames because of its durability.

Nylon. This frame material is still occasionally used. Nylon is strong, lightweight and flexible, but it can become brittle with age. For this reason, it has for the most part been replaced by nylon blends – polyamides, copolyamides and gliamides – which are more durable.

Combination frames

As you might guess, these are frames that have both metal and plastic components. Popular in the 1950s and 1960s, combination frames have made a comeback recently, in a wider variety of colors than the classic models.

Mix it up!

Each frame material offers its own advantages and style features. For eyewear that fits every occasion in your life, consider purchasing more than one pair of glasses and choose a different frame material for each pair.

For example, you may want a conservative-style frame made of durable, lightweight titanium for work. But on weekends, you may want something with more color or style, like a zyl frame in laminated colors, or a combination frame with a modern spin of that classic retro-look.

Source: Eyeglass Frame Materials article by AllAboutVision.com. ©2009 Access Media Group LLC.  All rights reserved.  Reproduction other than for one-time personal use is strictly prohibited.

 

Your eyeglass lenses are designed to correct your vision based on being held firmly in a fixed, stable position in front of your eyes. So when it comes to your eyeglass frames, it’s pretty easy to see why frame protection and maintenance is so important.

Many of us don’t realize how critical proper eyeglass frame alignment really is. But it’s why our eye care professional checks and double checks the position of our eyeglass frames in relation to face shape and size. The correct part of the lens needs to align properly in front of the eye for ideal vision correction.

Eyeglass frame protection maintenance isn’t time consuming—but it is a common sense, routine task you can perform to keep your vision in the clear. Here are tried-and-true ways to keep your eyeglass frames in mind. And in place.

Caring for eyeglass frames

Both hands, please! Eye care professionals suggest using both hands when putting on and taking off your glasses to avoid twisting or misaligning them. Gently grasp the frame arms of your glasses with equal pressure and carefully slide them on, lifting them over your ears. Use the same grip to remove them, sliding them up and forward.

Pay attention.When was the last time you actually took a good look at your frames? Periodically check your eyeglass frames to see if they are misaligned, and to test for loose screws in the frame arms. If the eyeglass frame looks twisted, or if your lenses seem to ride uneven on your nose, then it’s time to drop in on your eye care professional for a (typically free) adjustment. In addition, many drug stores sell inexpensive eyeglass tool kits containing a small screwdriver and an assortment of temple screws for emergency repairs.

Adjust early, adjust often. It’s a good idea to stop by your neighborhood optician to have your eyeglass frames adjusted. Many opticians will re-adjust your frames, whether you purchased your glasses from them or not. Even a slight adjustment can make an important difference in your healthy sight.

Don’t try this at home. Adjusting your eyeglass frames is not a do-it-yourself job. Your eye care professional is trained to know how your lenses need to be positioned relative to your eye. Also, an eyeglass frame can contain fragile materials and design elements. You might just snap them in your effort to fix them. That means no bending of frame arms!

Don’t forget to wash.Just as you need to wash your lenses, you need to wash your eyeglass frames. Regularly. With soapy water and a soft cloth.

Not on your head, not on the floor, not by the sink… Storing eyeglass frames on your head can stretch and misalign them. Stepping on your glasses is the quickest way to twist them or break them. And the bathroom sink is a good recipe for soiled lenses as well as frames. Sturdy eyeglass frame cases exist for good reason.

Special thanks to the EyeGlass Guide, for informational material that aided in the creation of this website. Visit the EyeGlass Guide today!