Disclaimer

***Disclaimer*** I am not paid by, nor do I endorse, any of the products displayed on my blog. My goal is simply to clarify some of the confusion about buying and maintaining eyeglasses.

Monday, January 21, 2013

What are All These Numbers??

A single Vision prescription for distance, with no astigmatism prescription.  In the industry, we refer to this as a 'spherical prescription'.  The SPH notation indicates there is no astigmatism correction needed.
A single vision prescription for distance with astigmatism correction.  This one is written in - cyl.
Often a patient will come to me with prescription in hand, and ask, "How much did my prescription change?" or, "What do all these numbers mean?"  It's not easy to make sense of the small intricacies of your eyeglass prescription without a little background information.  I will try to get only as technical as I need, but please feel free to ask questions in the comment section.  Lets start out with a simple prescription:

You can see above there are two rows and several columns on your prescription.  The top row is labled OD (the abreviation for the latin word for 'right eye'), all of the numbers across the top row pertain to your right eye.  The OS column, then, pertains to your left eye.  The right eye will almost always be listed first.  So lets examine the columns then.  The column labeled "SPHERE" is where you will see whether a prescription is needed for distance ( indicated with a minus sign AKA 'nearsighted') near, (plus sign) or neither, indicated with the letters PL, standing for plano or zero.  This is representing the power of correction needed in order to clear things up.  The person with the perscription on the left needs glasses to see in the distance.  But there are numbers in the other columns as well.
The CYL and AXIS mean that this person also has astigmatism that needs to be corrected.  A lot of people become concerned when I mention they have astigmatism and exclaim, "No one ever told me I have that!"  Truth is, a large portion of the prescriptions I see in my office have astigmatism.  It simply means your eyeball isn't perfectly spherical (round) and that causes the light to split up when it enters your eye, instead of staying in one nice, straight line. 
The CYL column indicates the amount of astigmatism correction needed to clear things up, and can be written in either + form (usually by ophthalmologists) or in - form, like the photo above, which is the way most optometrists write their prescriptions.  When the prescription is in + Cyl form, it must first be converted to - cyl form in order for you to discern whether your prescription is truly + or -.  Here is an example of two different ways to write the same prescription:
+.75 -1.75x180
-1.00 +1.75 x90
You might have noticed that the middle number, the CYL stayed the same, but the sign changed.  To switch between the + cyl form and the - cyl form of the prescription, you simply agebraically add the CYL power to the sphere power, switch the sign of the CYL and change the axis by 90 degrees.  Lets say, for our example above, you were handed a prescription written in the + cyl form and needed to transpose it to the - cyl form.  We would first algebraically add the +1.75 + (-1.00) = +.75 (in optical, if there is no sign in front of the number, it is assumed that it is +) The amount of CYL stays the same, 1.75, but we change the sign from + to -.  The last step then, is to change the axis.  If the existing axis is 90 or more, bract 90 from it.  If the existing axis is 89 or less, we would add 90 to it.  Since our rx is 90, we would add 90 to it.  So our end result is the top prescription. +.75 -1.75x180.  Where the first number represents the SPHERE column, the second the CYL and the third(preceded by and x) indicates the AXIS. 
Still with me?  If you get your prescription in + cyl and don't feel like transposing it, any optician should be able to do this for you easily.  I am always willing to do this for you at no charge, just leave a comment. 
Now then, the AXIS.  This pertains to how we are directing the light, and it runs from 1 to 180 degrees.  Your axis generally doesn't fluxuate very much after puberty, so if you see a dramatic change( more than 15-20 degrees) from one prescription to the next, expect to feel a little disoriented when you pick your new pair.  Note: it is possible to have a prescription only for astigmatism. the prescription would look something like this:
Note the "PL" in the SPHERE column?  That means ther is no correction for farsightedness or nearsightedness, only astigmatism.
I'm going to skip ahead to the ADD box, on some prescriptions this may also be called NV for near vision.  If you have a number filled in here, it means you need bifocals.  I felt a few of you shuddering at the thought!  It is actually just a natural part of life.  There is a group of muscles in the eye (the ciliary body) that is responsible for adjusting the lens of the eye to focus on things near and far.  About the age of 40, most people notice that muscle starting to lose its ability to pull things into focus, particularily close up things or tiny writing.  This is the point where we start to hold things a little farther from our face, in order to get a proper focus.  Eventually, the muscle weakens to the point where we need a corrective lens to do what the muscles no longer can.  Unfortunately, these muscles can't be trained or exercised, but there are new options for corrective surgery for those who can't stand the thought of wearing bifocals.  The bifocal, reading or Add power will always be a + number, because it is magnifying what you are looking at.  I will discuss types of bifocals in another post. 

The other column on your prescription (sometimes abbreviated as Rx) is PRISM.  If you have numbers and symbols here, it means that there is some sort of muscle imbalance that is causing double vision.  Your doctor may prescribe a press-on prism (or, Fresnel prism) as a way to test out how it works and how you adapt before we grind the prism into your lens.  A prism redirects the way the light enters the eye, and helps pull your eye muscles in the desired direction to help you focus as a singular object instead of double objects. 


A bifocal prescripton with Prism and astigmatism, written in plus cyl.
There can be many different combinations.  Some people only need glasses for reading so the entire SPHERE, CYL and AXIS portion simply says PL SPH with an ADD.  If you are lucky enough to have a prescription like this, you can buy over-the-counter reading glasses (AKA 'readers') very inexpensively.  For all other prescriptions, however, it is best to see your optician to have your prescription filled.

Friday, January 18, 2013

Bits and Pieces: Eyeglass Parts

A full metal frame with decorative temple.  This type of temple bends down behind the ear and is most common.
Model: Tura 694 by Tura
Quite often I get a frantic phone call from someone who's broken their glasses.  Their tangable chaos is in pieces in their hands, and they are wondering how they are going to get to work, or even to my office, and whether or not the doohickey that came off of the thingamajiger is repairable.  Me being a helper, I want to be able to tell them whether or not to worry, but too many times people just don't know the proper name of the parts of their glasses, and it becomes a little "sticky" trying to "diagnose" problems over the phone. 
First of all, I'm going to preach.  ALWAYS have a back up pair of glasses.  It is not comfortable to get through your day when you can't see as well as you know you should.  Also, if your drivers license indicates that you need corrective eyewear for driving and you are caught without, that is only going to make a bad situation worse.
So lets talk frame parts. 
Often miscalled 'bows', 'bands', arms, feet,legs, 'riders' and even 'kickstands', the part that extends from the front of the glasses along the side of your head and over your ears is called the TEMPLE.  Many of the fitting issues involved with eyeglasses can be solved by adjusting the temples.  Temples come in many different styles and materials, some go straight back behind the ear and hug the head, but most bend down behind the ear to help the glasses to stay put. 

this type of temple does not bend down behind the ear
Model: Smarter by Jee Vice
The FRONT, then, is the entire front piece of the frame, including the eyewire, which holds the lenses in place, and the bridge/nosepads.
 Those little pads that cushion the weight of the glasses on your nose are called NOSEPADS, and they are attached to the NOSEPAD ARMS.  They also come in many shapes, sizes and designs.  Some snap into the arm, some screw into the arm, and some are clamped in. Many people mistake the nosepad adjustment is the culprit when their glasses are crooked or are sitting on an angle, but truly the only main functions of the nosepad are to cushion the nose, and the make the glasses sit higher/avoid slipping down the nose.  They do need to be properly adjusted in order to feel comfortable, and as the nosepad arm is the most susceptible to breaking during a do-it-yourself repair, it's best to see your optician for a good adjustment.
Nosepads are generally found on metal frames.
Not all frames have nosepads.  If you choose a frame that is made of plastic, you will generally not have nosepads to contend with.  The pros of not having nosepads?  It distributes the weight of the glasses evenly across the nose, which is more comfortable for most people.  The cons?  They are less adjustable overall.
Another important part of your glasses is the HINGE.  This is the area where the temple folds.  There are many different types of hinge including:
This durable double hinge has a patended design that compresses the spring instead of stretching it.  These hinges are far more durable than the standard single-barrel hinge
Model: Elasta 7171 by Safilo Group
This is a very uncomplicated hinge.  There is no spring, it simply opens and closes.
Model: Aero F12 by Match Eyewear
This is a single-barrell hinge, the most common of all types.  They do absorb some of the impact of eyeglasses, but the springs inside aren't designed to last more than a year or two.
A completely hingeless frame.  These are generally only found on drill mount frames, and do not hold up well.
Here another simple hinge.  It simply opens and closes, no spring.  These generally last a really long time, but in this case, it makes the frame very un-adjustable.

So what's my recommendation in the way of hinges?  If you are a person who replaces your glasses every 1-2 years, choose whichever style is most comfortable.  If you like to wear your glasses for longer than that, you should stick with springless types of hinges.  Your glasses will generally hold up much better over time.

Wednesday, January 16, 2013

Amy Framed Me!

Now that you know who works in the eyecare center or optical shop, let's talk about eyeglasses!
Some of the intimidation factor of making a pricey investment like eyeglasses, comes from no knowing much about the product.  While eyeglasses are too complex to learn about in one session, hopefully as time goes on, you will learn much from these posts.
To get started, I will introduce you to the the frame styles.  I often hear older patients talking about how limited their choices were in eyeglasses when they were a kid.  "They all looked the same, and we could choose brown or black."  I hear horror stories about being forced to wear cat-eye glasses or military-issue styles (think Drew Carey), and how crushing a blow it was to the wearer's self-esteem.  But now, there are millions of styles to choose from, from the ornate to the geek-chic (again, think Drew Carey), it's truly a buyer's market.  With competetive and complex designs, frames come in all shapes, materials, sizes and colors, but the tried and true have stood the test of time.  There are three main styles of frames that are most common today.
First, is the "Full frame" also sometimes referred to simply as a metal frame or a plastic frame, depending on the material it's made of.  In the industry, we call this a hide-a-bevel.  In the full frame, the frame material completely encloses the lens.  These frames are available in a number of different materials but the most common are metal (most commonly an alloy called Monel)  and plastic (AKA zyl or acetate).  The main difference?  Metal frames almost always have nosepads, and plastic frames almost never do.
Semi-rimless.  This is a combination of metal and plastic semi-rimless.  See the metal bridge piece?
Model: Marc by Marc Jacobs 457 by Safilo Group
Some semi-rimless frames are open on the side instead of the bottom.
Model: Helium 4115EA by Match Eyewear
A full frame in plastic.  There are so many choices in colors and style these days.
Model: Banana Republic Anissa by Safilo Group
A full metal frame, classic and timeless.
Model: Tura 694 by Tura
The next style that is common today, is the semi-rimless.  This frame has metal or plastic only on part of the frame, while a thin nylon cord holds the lens in place via a groove cut into the lens edge.  Because chipping is likely, a chip-resistent lens material (Trivex) is most highly recommended.  It will make your glasses last much longer and resist damage.
The last style that is popular today is called a drill mount frame.  This type of "frame" is really three pieces of frame that are held together by the lens itself.  Because your lens needs to be drilled through and also takes the brunt of any impact on the glasses, a chip-resistent material is necessary.  Of note: if you come across any drill mount frames that have screws/nuts holding the lens in, avoid them like the plague!  They often loosen and fall apart too easily and require steady hands for the near-constant maintenance they need.  Also, some of the drill mount styles come "hingeless".  I have seen far too many of them break where the hinge should be, and they are impossible to adjust.  I am not a fan of the hingeless models.
A drill mount frame with hinges.  A very lightweight and durable choice, but ladies beware: they don't hide wrinkles!
Model: Aero F12 by Match Eyewear
Here is a hingeless drill mount. 
Sometimes I have patients tell me, "I've been told I have to have a full frame because of my prescription."  There are some opticians who'd like to make decisions for you, or perhaps they just use a lab that isn't very good at mounting higher prescriptions.  The truth is, until your prescription gets up over -9.00, you can choose any of the three styles mentioned.  Are your lenses going to be thick? Yes.  Are they going to be visible to others? Yes.  Does that bother you?  That is not up to me to answer any more than if you will be happy wearing a bright purple frame.  A good optician will help you choose a few flattering styles, based on what you tell them you like/how you want to look, and give you the pros and cons of each, so you can make a decision based on what is important to you.  If you feel like you are not getting that kind of service, or if someone is telling you that you "can't" or "Shouldn't" choose certain styles due to your prescription, get a second opinion. 

Tuesday, January 15, 2013

What's in a Name?

Optician, optometrist, ophthalmologist, technicians, assistants. Obstetricians? (Um, wrong department!)
Who is and does what in an Eyecare center? In most retail optical centers (Walmart, Lenscrafters, Pearle Vision, Sam's Club, Eyemart, etc, etc, etc!) you will find optometrists, opticians, optometric technicians/assistants and sometimes a lab technician. They all have important, and sometimes changing roles.
When you schedule a routine eye exam, you will likely go to a optometrist, or as we like to call them, an OD. These two letters after their name indicate that they are optometrists, and not an ophthalmologist, who will have an MD following their name. Optometrists are concerned with the health of your eyes and your vision. With the help of an optometric assistant, the optometrist will test your acuity ( that's that 20/20 number, where you have to try and read the letters on the chart), and do a refraction ( the test where lenses of varying powers are placed in front of you and you have to answer a slew of questions about which looks better, one or two). Optometrists can also check for diseases of the eye, and can often catch other diseases like diabetes, high blood pressure, thyroid problems, stroke, brain tumors, even MS. And that's just to name a few. Many diseases cause vision issues. In short, there isn't much an OD can't do when it comes to eyes.
Surgery, however, is one of the things you would need to see an ophthalmologist for, and management of medical eye problems like glaucoma, genetic defects or cataracts that are ready to be removed. Ophthalmologists can also give a very thorough eye exam, but generally they don't do the refraction (the "which looks better test"), but have an assistant or technician do that test. Why is that important? Because your prescription is the result if how you answer those questions. In my experience, I have much better success when the optometrist writes the Rx (prescription), as opposed to an ophthalmic assistant or technician. I mean no offense to anyone, I'm just speaking from my personal experience of what happens when I dispense the glasses afterword. While there are dozens of reasons you can or cannot see out of your glasses, getting an accurate refraction is an essential part of the equation.
An optician, then, is the one who helps you select your glasses and customizes the lenses so you get the clearest vision possible. I believe my job is to give my patient information with which they can make informed decisions whether or not they purchase their glasses from me. There are plenty of companies that don't see it that way, they care only to fatten their bottom line by putting harsh sales quotas on opticians, forcing them to recommend unnecessary upgrades just to meet quotas. One of the top selling eyeglass companies in the world does this, I know because I worked for them for 5 years, and when they told me that they were giving me a pay cut due to my not meeting quotas, I left. I am a helper by nature, sales is simply a part of what I do. I do not sell anything that I personally don't believe in, and I never recommend unnecessary upgrades.
Opticians can have many other duties depending on the office and state opticianry/optometric laws. I've already worked as an optometric assistant, pre-examining patients, I've done insurance billing, appointment scheduling, contact lens training classes, eyeglass inspection, and inventory management, to name a few, all under the title of optician. And in stores that make glasses while you wait, some opticians make or cut lenses as well.
The lab technician is generally the person in charge of making your lenses and inserting them into the frame. If you want to know about the how's and whys of eyeglasses, no one is more knowledgable than a lab tech. I have oodles of respect for them as they are generally overworked and underpaid, and there would be no eyeglasses without them.
I am fortunate to work in a health clinic that has optometrists, ophthalmologists, a retinal specialist ( retinal detachment, macular degeneration) and a vision therapist, who helps people with low vision learn how to adapt to their world. My little part in the optical department ( AKA the eyeglass shop) is tiny compared to the great things the doctors and their staff are doing, but to me, the world of eyeglasses is fascinating and I wouldn't want to switch jobs with them for anything!

Welcome!

Welcome eyeglass wearers! Whether you love them or hate them, most people end up needing glasses at some point in their lives. With the dizzying array of frame and lens materials and designs, it's hard to make sense of it all! And in today's crazy world, who had time to research?
That's where I come in. I've been an optician since 2001, and my journey has taken me through two certifications, many hours of instruction, apprenticeship, and getting licensed in one of the toughest states to pass the boards. I've made mistakes along the way, helped a lot of people and learned a lot. My most important lesson? As much as you know about optics, there is still way more to learn. A lot of it involves physics, and a great deal of patience. But with equipment getting more technical, things we never thought possible are coming to life in front of us.
This blog is to help inform you about eyeglasses, to give you a little information to help answer some questions you may have about glasses, so the choices will be less confusing. I hope you find it useful, and aren't intimidated to ask questions. I'm here to help!



Amy A.
ABO,NCLE,NVDO#424