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Posts tagged ‘eyeglasses’

Slim, Nice Figure, Ideal Weight and Attractive. What’s Being Described Here?

hi index eyeglass lensesIf you answered eyeglass lenses, you are correct!

Hi-index lenses offer people who wear eyeglasses with lens choices that are thin, light and attractive.

For people who have strong prescriptions for nearsightedness, farsightedness or astigmatism, hi-index lenses are a great way to avoid lenses that are thick, heavy and distort the natural appearance of your eyes.

The lenses in a pair of eyeglasses correct vision by bending or refracting light as it passes through each lens.  With conventional plastic and glass lenses, the more light that needs bent, the alternatives to thick eyeglassesthicker the lenses must be.

Hi-index lenses are different.  Here’s how they work and the benefits they offer:

Increased Light Bending Abilities

Hi-index lenses are made of a special material that is able to bend or refract light much more efficiently than conventional lenses.  This means less lens material needs to be used to bend the appropriate amount of light that corrects vision.

Thin Construction

Due to the increased ability to bend light, hi-index lenses are much thinner than conventional plastic and glass lenses. Therefore, the profiles of eyeglasses are not dominated by thick lenses when hi-index lenses are used.

Comfortable Wear

Because less material is used with hi-index lenses, they do not weigh as much as conventional lenses. This makes them light weight and comfortable to wear.

hi index lenses for eyeglassesAttractive

The fashions of today’s most popular frames have either very thin rims or no rims at all (rimless frames). The thickness of the lens becomes very important with these styles of eyeglass frames.  When lenses are too thick, the balance between the frames and lenses becomes disproportionate, resulting in a pair of eyeglasses that are not as cosmetically appealing as they could be with hi-index lenses.

Ask Your Eye Doctor About Hi-Index Lenses

Discuss hi-index lenses with your eye doctor to see if they are an option for you and your vision correction needs.  They may provide you with the function, comfort and appearance you desire in a pair of eyeglasses.

Learn more about quality eye care and eye wear from a company and a team of eye care professionals who have been providing a superior level of service for more than 35 years. Please visit www.shawneeoptical.com.

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Three Main Types of Retinal Detachment

Eye anatomy and eye careThe retina is a thin, light-sensitive membrane covering the rear of the eye. It’s the part of the eye where images are focused by the cornea and lens. The images displayed on the retina are transmitted to the visual centers of the brain by the optic nerve. In fact, the retina is technically part of the body’s central nervous system and is considered brain tissue.

Approximately 95% of the retina is responsible for side vision or peripheral vision. The remaining 5% located in the very center of the retina is known as the macula and allows for central vision.

If the retina becomes damaged or separates from the back wall of the eye, it’s a condition known as retinal detachment.  When a retinal detachment occurs, it’s a serious condition that needs attention. A retinal detachment causes the retina to separate from its blood and nutritional supply which could lead to loss of peripheral vision, central vision or both.

There are three (3) main types of retinal detachment:

retinal detachmentRhegmatogenous Retinal Detachment (RRD)

This is the most common type of retinal detachment. The term rhegmatogenous means “arising from a rupture or a fracture”.  Rhegmatogeous retinal detachment occurs when there is a hole or a tear in the retina. The break in the retina allows the gel-like substance from the vitreous cavity of the eye to seep through the opening causing the retina to detach from the eye wall.

Tractional Retinal Detachment (TRD)

A tractional retinal detachment is a retinal detachment caused by the gel like substance within the vitreous cavity of the eye pulling on the retina which eventually causes the retina to detach from the rear eye wall.

Exudative Retinal Detachment (ERD)

An exudative retinal detachment occurs as a result of a leak under the retina which allows the gel-like vitreous substance to enter behind the retina. These types of leaks are typically caused by inflammation.

Symptoms of Retinal Detachment

Flashing lights and eye floaters are common early symptoms associated with a retinal tear or retinal detachment.  If a dark shadow or dark curtain obscures a portion of vision, this is also an indicator of retinal detachment.  Anyone who experiences these symptoms should schedule an exam with their eye doctor immediately.

Learn more about quality eye care and eye wear from a company and a team of eye care professionals who have been providing a superior level of service for more than 35 years. Please visit www.shawneeoptical.com.

Can Your Student See the Blackboard – or Rather, Whiteboard at School?

Vision and LearningRemember when teachers used to write with chalk on blackboards? Today, those blackboards, chalk and erasers have been largely replaced with whiteboards, markers and Power Point presentations.

The question parents and teachers ask their students still remains just about the same:

“Are you having any trouble seeing the blackboard whiteboard at school?”

Parents and teachers know vision plays a vital role in a student’s ability to learn.  In today’s technology driven world, a student’s reliance on clear vision for learning is greater than ever. Research studies show a direct link between vision and a student’s performance in the classroom.

More Information Learned Visually

Various research studies conducted in educational theory show that visual learning is among the very best methods for teaching students of all ages how to learn.

According to the research, students remember information at a much higher rate when that information is presented visually.

Visual Clarity Improves Learning 

Studies also show that visual clarity of the information being studied greatly impacts the ease at which it is learned and the attitude of the student.  Students have a positive approach to the information if they can see it clearly and easily. This has huge implications on learning. A student’s feelings and perceptions about learning determine the student’s level of motivation, comprehension and retention. Crisp and clear vision is critical for optimal academic performance. If a student has a vision problem, they are likely to be frustrated with school and develop a poor attitude towards their education.

Color Vision for Whiteboards and Computer Screens

The increasing use of whiteboards and Power Point presentations in the classroom allow teachers to use a wide variety of colors in their teaching. If a student has an issue with their color vision (color blindness), they may not be able to see or distinguish important parts of the teacher’s presentation. This can have a significant impact on understanding a teaching lesson and learning. Boys are more likely to have issues with color vision than girls.

Importance of Regular Eye Exams

Academic performance is yet another reason why attending regular scheduled eye exams are so important. Talk to your eye doctor about your child’s academic performance and whether they are having trouble seeing the information presented to them in the classroom. It can be surprising how well a student’s grades improve when vision problems are corrected.

Learn more about quality eye care and eye wear from a company and a team of eye care professionals who have been providing a superior level of service for more than 35 years. Please visit www.shawneeoptical.com. While on the website, notice the special eyeglass frames offered just for children. Shawnee Optical’s KidSpecs program provides kids of all ages with hundreds of frames choices. After all, kids want to look good too!

Children Shouldn’t Be Scared of Cycloplegic Refraction

Cycloplegic refraction explained by Shawnee OpticalThe term “cycloplegic refraction” certainly sounds intimidating. Tell this to a child and it can be understandably frightening.  As with many unknowns, a little knowledge and setting expectations can take away unnecessary fears.

What is Cycloplegic Refraction?

Cycloplegic refraction is nothing more than a procedure used by eye doctors to gain an accurate reading of a person’s refractive error to help them see more clearly and comfortably.

Refractive error is the inability of a person’s eye to bend light correctly. If light is not refracted properly as it enters the eye, the result is distorted vision.

During the testing in an eye exam, a patient’s eyes may auto- focus, or accommodate, which leads to inaccurate and inconclusive testing results. When your eyes are auto focusing, your eye doctor cannot decisively determine your true eye prescription.

Cycloplegic refraction temporarily stops the eye’s ability to auto focus allowing your eye doctor to correctly ascertain your prescription and optimize your ability to see clearly and comfortably.

Why is Cycloplegic Refraction Common with Children?     

Cycloplegic refraction is often times used with children. Children have a strong ability to unknowingly accommodate, or auto-focus, their vision which makes eye exams yield inaccurate or incomplete results.

As described above, cycloplegic refraction briefly suspends a child’s ability to auto-focus. This provides the eye doctor with an uninterrupted opportunity to obtain an exact reading on the child’s refractive error and derive a true and accurate prescription.

What to Expect with Cycloplegic Refraction

Cycloplegic eye drops are placed in the patient’s eye to prevent the ciliary muscle of the eye from contracting and relaxing. This muscle is attached to the crystalline lens of the eye and controls the shape of lens.

There are a variety of cycloplegic eye drops which differ in strength and duration.  When these eye drops are applied, it causes the pupils to dilate and vision will become blurred for a few hours. Some patients also experience tearing and redness in the eyes.

Not Just for Children

Cycloplegic refraction is not exclusively for children. Adults sometimes need this procedure performed to gain a more precise eye prescription. If eyeglasses do not provide the level of clarity needed, this procedure may be appropriate to deliver a refined eyeglass prescription.

Learn more about quality eye care and eye wear from a company and a team of eye care professionals who have been providing a superior level of service for more than 30 years. Please visit www.shawneeoptical.com.

Eye Glasses: a History and the Future

eye glasses Shawnee OpticalEye glasses are in the process of changing significantly. The eye glasses of tomorrow will be noticeably different than the variety of lenses and frames being offered today.

Eye Glasses History Lesson

Historians generally give credit to Italian monks for fabricating the first pair of eyeglasses at some point between the years 1285 – 1290. These spectacles, as they were commonly called, were used for reading.  Eye glasses to correct distance vision are estimated to have been crafted in the early 1400’s.

One of our Founding Fathers, Benjamin Franklin, invented bifocal lenses in the year 1784 which allowed for correction of both distance vision and near vision in the same lens. An Englishman, Sir George Airy, designed lenses to correct astigmatism in 1825.

Trifocal lenses which have three specific powers (one for near vision, one for intermediate vision and one for distance vision) were produced by inventor and musician John Hawkins in the year 1826.

In 1958, Essilor International introduced progressive multifocal lenses which further enhanced lenses with multiple powers for distance, intermediate and near vision.

Innovations in Eye Glasses

Technology is playing an increasing role in the evolution of eyeglasses. Lenses have been developed and continue to be refined whereby the entire lens adjusts with your vision needs.

Electronic eye glasses have been designed with a special type of lens filled with a clear crystal liquid layer that can be electronically controlled automatically or manually. A touch of the finger to the side of the frames or a tilt of the head in a certain direction changes the entire lens to serve your vision needs. If you want to read something, a tilt of the head downward will cause the eyeglasses to automatically adjust the entire lens for near vision. A split-second swipe of the finger across the temples of your frames will allow you to look up from what you were reading and see a distant object clearly through the convenience and comfort of the entire lens.

Electronic glasses are powered by a battery and need to be re-charged. They are currently offered to the public but as you may guess with any emerging technology, they are rather pricey today.

Computing via Eyeglasses

While not targeted towards vision correction, electronic display eyeglasses are being developed that use eye movements to control presentation of information. These eyeglasses contain a microchip that takes data from a PDA (Personal Digital Assistant) and displays it directly on the person’s retina, creating an illusion that the images and text are a few feet away. Eye movements can control menus, search information, play video and conduct many other tasks routinely performed on desktops, laptops and mobile devices today.

This advancement in eye wear is still in the prototype phase. The technology is not yet at a point where its purchase and every day use are feasible.

Discuss emerging eye wear technologies that may serve your unique vision needs, lifestyle and budget with your eye doctor at your next eye exam. The options and the choices are changing.

To learn about a company and a team of eye care professionals that have been providing their patients with quality eye care and eye wear for more than 30 years, please visit www.shawneeoptical.com.

How The Lenses of Eyeglasses Are Made

The function of an eyeglass lens is to bend rays of light so that when they enter the eye they focus perfectly on the eye’s retina. This idea of using lenses to improve faulty vision goes back many centuries. While the technology, equipment and precision used in the process of making lenses have changed exponentially in recent years, the basic steps in creating a prescription lens have remained largely the same for the past 50 years. Here’s how eyeglass lenses are made: 

Start with Lens Blanks
The process of creating a prescription eyeglass lens begins with large buttons of lens material that look like clear hockey pucks. These lens blanks are typically injection molded and mass produced using a variety of plastic resins. The front side of these lens blanks have set curvatures that define the nature of the lens. Single-vision lenses, bifocals, trifocals and the myriad of progressive addition lenses each have a unique front surface. Lens manufacturers often put millions of dollars into engineering the precise front curvatures of their progressive addition lenses (just in case you were wondering why your eyeglasses cost so much).

Step 1 – Surfacing
Once the technician selects the proper lens blank, he mounts it to a carrier block made of wax or lead alloy and inserts it into a lens lathe. Using computer settings dictated by your eye doctor’s prescription, the lathe shaves layers of material off the back side to create very precise curvatures and the desired thickness. It is the combination of the front side curvatures and the back side curvatures that determines how the lens will bend the light rays to correct various degrees of myopiaor near sightedness, hyperopia, or far sightedness, presbyopia, or reading vision, and astigmatism.

Step 2 – Fining
When the lens comes out of the lathe, the back side is somewhat rough. This gives it a frosted appearance. The technician now puts the lens on a fining machine, which uses a precisely tooled polishing block, called a lap, to polish the back side of the lens. The convex side of the lap is covered with a pad that is impregnated with a fine grit and is then mechanically agitated against the concave surface of the lens until the lens is totally clear. To picture this, make a fist with one hand, and then drape your other hand over the top of it and rotate your palm. That’s the fining process.

Step 3 – Edging
Now that the prescription has been ground in and polished, the lens is much thinner than when it started, but it is still the diameter of a hockey puck. The next step is to cut the lens down to size. In most labs today this is done with a computerized lens edger. The newly surfaced lens goes into the edger along with the frame you have selected. The edger uses a digital tracer to capture an exact three-dimensional image of the frame and then, using the fitting measurements provided by your optician, the edger passes the lens over a diamond cutting wheel until it is reduced to the proper size and shape.

Step 4 – Coatings 
Now the lens is ready for finishing touches. For example, lenses can be specially coated to resist scratching, to block ultraviolet light or to reduce reflections. Anti-reflective coatings are a rapidly growing segment. In dust-free coating equipment, the lens typically receives up to 16 ultrathin layers of metal oxide coating. These various layers combine to dampen glare, repel water and sometimes repel oil.

The Future of Eyeglass Lenses is Getting Clearer
While the vast majority of eyeglass lenses made today follow the procedures above, new technology is entering the market. Knowledge developed in the refinement of LASIK eye surgery is rapidly making its way to lens laboratories. The same concepts that doctors use to custom “carve” a patients cornea during LASIK surgery can be applied to plastic lenses. This emerging science, known as wavefront technology, will ultimately make lens blanks a thing of the past. New wavefront lens lathes will custom carve the front and back surfaces of lenses, resulting in greatly reduced visual distortion and improved lens clarity.

To learn more about eyeglasses, eyeglass lenses, proper eye care, eye wear and Shawnee Optical, please visit our website at www.shawneeoptical.com.   

The Unavoidable Facts About Bifocals, Part 2

Treating Presbyopia (Eye condition which necessitates bifocals) with Contact Lenses: 

For years contact lens wearers considered the onset of presbyopia to be the time to make the forced switch fromcontacts to eyeglasses. Many are finding that this need not be the case. While contact lens manufacturers scramble to be the first to perfect and market a functional bifocal contact lens, the public has not embraced them in huge numbers. Meanwhile, more and more contact lens wearers are finding that they can treat their presbyopia with Monovision contacts.

Monovision doesn’t denote any special type of contact lens, but rather a special type of contact lens fitting. With monovision, the doctor fits you with a contact lens to correct one eye for distance vision while fitting your other eye with a contact lens for near vision. While this arrangement may sound unorthodox, monovision has been proven to be effective. Erie, Pennsylvania Optometrist James Piersol estimates, “Over eighty percent of my presbyopic patients who try monovision are ultimately successful with it. It normally takes one or two fittings to get the power balanced  properly, but once you do, the patient rarely can tell that each eye is performing a separate function.” Monovision is actually not as far-fetched as it sounds. Dr. Piersol explains, “The brain is always receiving two separate images from your eyes. It normally takes the two similar images and fuses them into one three-dimensional image. With monovision, the brain receives two very different images, one clear only at distance the other clear only at near. Since it can not fuse them into one picture the brain simply chooses between the two images based on the immediate task at hand, much like a director choosing between two camera angles”.

Skeptical? Try this experiment. Take a paper towel tube and with both eyes open look at your television screen. Now alternately close your right eye and then your left. The image from your dominant eye (the right for most people) will hardly move at all while the image from your non-dominant eye will jump noticeably. This is because as you sit there watching TV your brain is “choosing” the image from the dominant eye. If you were being fit for monovision the dominant eye would be fit for distance and the non-dominant eye would be fit for reading.

While monovision contacts do offer a proven and cost effective treatment for presbyopia, they also have a down side. Since your brain would be receiving only one image for distance and only one image for near, there is a resulting reduction in depth perception. This can be a critical problem for some people’s occupational requirements.

Treating Presbyopia with Surgery:

One reason for the growth in monovision contact lens fits is the rising interest in corrective eye surgery. While the public continues to warm to the idea of LASIK and other surgical procedures to correct distance vision, a medical correction is now emerging for near vision. It is called conductive keratoplasty, or CK. CK is a non-invasive procedure where radio waves are used to reshape the cornea in order to improve focus at near. The procedure is quick, relatively painless and a bit pricey. Because CK is done on only one eye the final result is very much like monovision without the contact lenses. That being the case, most people prefer to test their tolerance for monovision with contact lenses before moving on to the permanence and expense of CK.  Since presbyopia advances with age anyone considering CK needs to understand that additional procedures may be required every 3 to 5 years to keep up with their increasing presbyopia.

In the first 200 years after Ben Franklin invented the bifocal there were virtually no changes. Your father’s bifocals were very much like your great-great grandfather’s bifocals. By contrast, in the past 5 years over 176 differentProgressive Addition Lenses (PALs) have hit the market.  Each one is somehow superior to those that came before. The technology is improving exponentially.  Before too many years pass we’ll see doctors inject soft polymer plastic into the eye’s lens sac and thereby restore the lens’s flexibility. At that point it will be bye-bye bifocals.

To learn more about proper eye care, eye wear and Shawnee Optical, please visit our website at  www.shawneeoptical.com.  

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