Types of Cataracts

A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil.

Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. In fact, there are more cases of cataracts worldwide than there are of glaucoma, macular degeneration and diabetic retinopathy combined, according to Prevent Blindness America (PBA).

Today, cataracts affect more than 22 million Americans age 40 and older. And as the U.S. population ages, more than 30 million Americans are expected to have cataracts by the year 2020, PBA says.


Types of cataracts include:

A subcapsular cataract occurs at the back of the lens. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract.

A nuclear cataract forms deep in the central zone (nucleus) of the lens. Nuclear cataracts usually are associated with aging.

A cortical cataract is characterized by white, wedge-like opacities that start in the periphery of the lens and work their way to the center in a spoke-like fashion. This type of cataract occurs in the lens cortex, which is the part of the lens that surrounds the central nucleus.

No one knows for sure why the eye's lens changes as we age, forming cataracts. But researchers worldwide have identified factors that may cause cataracts or are associated with cataract development. Besides advancing age, cataract risk factors include:

If you think you have a cataract, see an eye doctor for an exam to find out for sure.

By Gretchyn Bailey

Hey! My Arms Shrunk!

We know what you're thinking...who shrunk my arms? It's happening a lot around the office at Skyvision Centers, too. We're all getting a little older  around here and it seems like there are a bunch of reading glasses lying around everywhere now. As a matter of fact, the only person in the office who can't seem to find Dr. White's readers is DR. WHITE!

Why do we start to have trouble reading when we get older? To answer that we have to go all the way back to age 2 or so. Almost all of us is born a little farsighted or hyperopic. We focus our eyes to overcome this little bit of farsightedness using the same muscles that we use to focus on objects up close. This muscular process is called ACCOMMODATION. When we look at things up close three things happen: our eyes come closer together, our pupils get smaller, and the lens inside our eyes gets fatter. We have massive powers of accommodation at age two and then we gradually lose those powers as wel get older.

The medical term for "Over 40 Eyes" is PRESBYOPIA. When we lose enough of our power of accommodation that we can no longer see things up close we become presbyopic. Of course your kids will just say you got old! Here's a LINK to the Eyemaginations video on presbyopia.

So what can we do? Well, there are a bunch of options, actually. If your eyes are health you can just buy reading glasses at the pharmacy. You might have a different prescription in each of your eyes, and if so your Skyvision Centers eye doctor can prescribe a pair of reading glasses that are specific to you. Many of us need to wear glasses to see things far away--a pair of bifocals takes care of the up-close problem. Bifocal contact lenses are available, and you can even correct your vision with something called MONOVISION, with one eye corrected for near and one eye corrected for far vision.

Whew! That's a lot of options! Don't worry...we'll have lots of answers for you in future posts, and of course,  you can go to the SkyVisionCenters101 YouTube channel see several "Dr. Whiteboard" videos about bifocals!

Visual Field Testing

During a routine eye exam, some eye doctors may want to determine through visual field testing the full horizontal and vertical range of what you are able to see peripherally. This range is commonly referred to as "side vision."

Visual field tests assess the potential presence of blind spots (scotomas), which could indicate eye diseases. A blind spot in the field of vision can be linked to a variety of specific eye diseases, depending on the size and shape of the scotoma.

Many eye and brain disorders can cause peripheral vision loss and visual field abnormalities.

For example, optic nerve damage caused by glaucoma creates a very specific visual field defect. Other eye problems associated with blind spots and other visual field defects include optic nerve damage (optic neuropathy) from disease or damage to the light-sensitive inner lining of the eye (retina).

Brain abnormalities such as those caused by strokes or tumors can affect the visual field. In fact, the location of the stroke or tumor in the brain can frequently be determined by the size, shape and site of the visual field defect.

Types of Visual Field Tests

Confrontation visual field testing typically is used as a screening visual field test. One eye is covered, while the other eye fixates on a target object, such as the doctor's open eye, while the doctor stands or sits directly in front of you. You then are asked to describe what you see on the far edges or periphery of your field of view.

If an eye disease is suspected, you may need to undergo more comprehensive, formal types of visual field testing to evaluate the quality of your central and peripheral vision.


The picture to the right shows a patient who doing visual field testing with a Humphrey Field Analyzer (HFA), which uses automated perimetry to measure responses to visual stimuli appearing in central and side vision. (image by Zeiss)     By Marilyn Haddrill; contributions and review by Charles Slonim, MD

Detection and Treatment of Refractive Errors

Your eye doctor determines the type and degree of refractive error you have by performing a test called a refraction.

This can be be done with a computerized instrument (automated refraction) or with a mechanical instrument called a phoropter that allows your eye doctor to show you one lens at a time (manual refraction).

Often, an automated refraction will be performed by a member of the doctor's staff, and then the eye care practitioner will refine and verify the results with a manual refraction.

An eye care practitioner performs a manual refraction. Your refraction may reveal that you have more than one type of refractive error. For example, your blurred vision may be due to both nearsighted and astigmatism.

Your eye doctor will use the results of your refraction to determine your eyeglasses prescription. A refraction, however, does not provide sufficient information to write a contact lens prescription, which requires a contact lens fitting.

Eyeglass lenses and contact lenses are fabricated with precise curves to refract light to the degree necessary to compensate for refractive errors and bring light to a sharp focus on the retina.

Vision correction surgeries such as LASIK aim to correct refractive errors by changing the shape of the cornea, so that light rays are bent into a more accurate point of focus.

by Gary Heiting, OD

Thoughts From Dr. White on Newtown, CT

Dr. White has a blog where he sometimes shares his thoughts on life and stuff. Here is what he wrote this weekend about the tragedy in Newtown, CT.

I’m the words guy. There’s no word here. You’ve probably heard or seen this before. In every language, as far as I know, there is a word that describes the state of having lost a family member. Widow or widower, orphan.

There is no word in any language that I know that so names a parent who has lost a child. Think about that. This is such an unnatural state, so upside down, that the a signature trait that defines us as a species (complex language) is silent. All of the various languages that reflect countless cultures both current and long gone, and not a single word that immediately conjures an image as accurately as “orphan” for those who have buried their offspring.

Not a single word.

We are now in the middle of the Christmas holiday season in the Christian world. The suburban version includes various and sundry versions of the “Christmas Party”. Beth and I attended two last night. I had, oh, 50 or so distinct conversations. 50 little “Groundhog Day” chats catching everyone up on my own children. For my part I asked only one question: “how are your kids?” I imagine something more similar than different everywhere in the world when parents gather.

“How are the kids?”

Randy and I attended a really moving CrossFit event yesterday, one in which a really significant sum was raised to aid the family of a handicapped child (kudos to CrossFit Cleveland). We met a couple of brand new Moms with first borns velcro’d or strapped or otherwise attached in parenthood 1.0. I’m one of the “wise old men” of the local CF scene (hey, when did THAT happen?), and I shared with these young Moms my view that the arrival of your first child is the single biggest life-changing moment one can experience. I always say that, and the young Moms and Dads always shake weary heads and sleepy eyes in agreement, and I silently pray as I speak that the words I’ve spoken will ring ever true, for I know in my heart that I am lying to these children holding their children.

The single biggest life-changing moment one can experience is to learn that you have lost your child.

You know someone who has heard this news; we all do. They are never the same. They will never be the same. I meet people in their 80′s who lose a child in their 60′s and honestly, it looks the same. It’s unnatural. It’s not the way it’s supposed to happen, no matter how it happens. It’s so upside down that we have no word for the survivors.

I know that I am lying to these young parents because I once stood on the edge of this abyss. Stood so close that if I let myself lean just a little bit I could look over the edge, see the blackness, the emptiness, the cold. Nothing, and I really do mean nothing, has affected me ever in my life as profoundly as that one quick look, that one peek that I just couldn’t keep myself from taking at what life would be like if I’d lost my child. I can’t shake it. It’s been years and I can’t shake it. It informs everything about my life, how I live my life, how I find the good in most everything, the fact that I was not plunged into the abyss. I did not lose my child. My child lived.

There is really no lesson here, Dear Friends. No teachable moment today, just a most sincere hope and prayer for each and every parent among you that you will never stand at the edge of that abyss, let alone be plunged into its depths. Just the most sincere hope that there will continue to be a word that describes you throughout your life, as my wife Beth and I have thankfully continued to be blessed. Indeed, there is a word in every language in the history of our species to describe those so blessed, a name for each of us.

Mom or Dad.

Visual Acuity Testing

Visual acuity tests are used to evaluate eyesight. Several types of visual acuity tests may be used.

The Snellen test checks your ability to see at distances. It uses a wall chart that has several rows of letters. The letters on the top row are the largest; those on the bottom row are the smallest. See a picture of a Snellen chart .

You will stand or sit 20 ft (6 m) from the chart and be asked to cover one eye and then read the smallest row of letters you can see on the chart. If you are unable to cover your eye, an eye patch will be placed over your eye.

Each eye is tested separately. You may be given a different chart or asked to read a row backward to make sure that you did not memorize the sequence of letters from the previous test.

If you wear glasses or contacts, you may be asked to repeat the test on each eye while wearing them.

Let your health professional know if you have trouble reading the letters on one side of the row, or if some letters disappear while you are looking at other letters. You may have a visual field problem, and visual field tests may be needed.

The E chart tests the vision of children and people who cannot read. The E chart is similar to the Snellen chart in that there are several rows, but all of the rows contain only the letter E in different positions. The top row is the largest and the bottom row of Es is the smallest. You will be asked to point in the same direction as the lines of the E. Similar charts use the letter C or pictures. These charts are also available in a handheld card. See a picture of an E chart .

The Near test uses a small card (Jaeger chart) containing a few short lines or paragraphs of printed text to test your near vision. The size of the print gradually gets smaller. You will be asked to hold the card about 14 in. (36 cm) from your face and read aloud the paragraph containing the smallest print you can comfortably read. Both eyes are tested together, with and without corrective lenses. This test is routinely done after age 40, because near vision tends to decline as you age (presbyopia).

If you cannot read any of the letters or print on these charts because of poor vision, your visual acuity will be tested by other techniques, such as counting fingers, detecting hand movements, or distinguishing the direction or perception of light sources (such as room light or a penlight held up close to the face).

Visual acuity tests usually take about 5 to 10 minutes. They may be performed by a nurse, a medical assistant, an ophthalmologist, an optometrist, a teacher, or some other trained person. Testing may be done at a doctor's office, school, workplace, health fair, or elsewhere.

Vision Tests

Have You Wondered What All The Different Vision Tests Are For?

Vision tests check many different functions of the eye. The tests measure your ability to see details at near and far distances, check for gaps or defects in your field of vision, and evaluate your ability to see different colors.

Visual acuity tests are the most common tests used to evaluate eyesight. They measure the eye's ability to see details at near and far distances. The tests usually involve reading letters or looking at symbols of different sizes on an eye chart. Usually, each eye is tested by itself. And then both eyes may be tested together, with and without corrective lenses (if you wear them). Several types of visual acuity tests may be used.

Refraction is a test that measures the eyes' need for corrective lenses (refractive error). It is usually done after a visual acuity test. Refractive errors, such as nearsightedness or farsightedness, occur when light rays entering the eye can't focus exactly on the nerve layer (retina) at the back of the eye. This causes blurred vision. Refraction is done as a routine part of an eye examination for people who already wear glasses or contact lenses, but it will also be done if the results of the other visual acuity tests show that your eyesight is below normal and can be corrected by glasses.

Visual field tests are used to check for gaps in your side (peripheral) vision. Your complete visual field is the entire area seen when your gaze is fixed in one direction. The complete visual field is seen by both eyes at the same time, and it includes the central visual field-which detects the highest degree of detail-and the peripheral visual fields.

Color vision tests check your ability to distinguish colors. It is used to screen for color blindness in people with suspected retinal or optic nerve disease or who have a family history of color blindness. The color vision test is also used to screen applicants for jobs in fields where color perception is essential, such as law enforcement, the military, or electronics. Color vision tests only detect a problem-further testing is needed to identify what is causing the problem.

More information regarding these different tests to come . . . .

Snow Blindness

Well, if you live in Cleveland you KNOW why we're putting this post up!    We are known to have  some pretty crazy weather around here.  Quite a few of our patients will notice how bright it is when the sun is out and the snow is on the ground, and some of them were worried about Snow Blindness. So what, exactly, IS snow blindness, anyway?

Ultraviolet light in high doses is actually toxic to many parts of the eye. The cornea, the window to the eye, is especially affected by exposure to these high doses. In fact, welder's flash is actually an ultraviolet "burn" to the cornea. There is lots of UV light in sunlight. On snowy landscapes when the sun is out the UV light is not only transmitted directly into the eye from above, but it is reflected and CONCENTRATED or focused by the snow crystals on the ground.

Snow blindness is a kind of UV damage to the cornea. That's why you always see pictures of mountaneers wearing sunglasses with side shields, or very dark goggles.Same thing for skiers, if they are being smart about eye protection!

Can you get snow blindness here in Cleveland just from your daily activities? Well, probably not. At least not unless you are a park ranger in our Emerald Necklace of Metroparks!

I Have Flashing Lights And I See Bugs!

 One of the most common symptoms patients share with us usually go something like this: "HELP! I'm seeing black things flying around in front of me and no one else can see them." Or "there's lightening in my house!" Flashing lights and dark floaters are things that bring patients in to see us every day.

The most common cause of "Flashes and Floaters" is changes in the vitreous jelly, the jell that fills the center of the eye. The vitreous is very important for the development of the eye until we reach the age of 2. After that it's just there to cause mischief! One of the mischievious things it does is shrink. In the beginning stages of this shrinking the microcsopic protein skeleton that makes the vitreous a jell collapses on itself and you get bits of protein debris...FLOATERS!

In time the vitreous shrinks to the point where it starts to separate from the inside of the eye. When this happens the vitreous tugs on the retina. It doesn't matter what you do to the retina it will give off a sensation of light. So, when the vitreous contracts and puts some pulling on the retina you get a FLASH!

The danger, of course, is that when the vitreous pulls itself off the retina it can take a piece of the retina with it, causing a hole or a tear. That's why it's important to call your Skyvision Centers eye doctor and come in for a visit if you have new FLASHES AND FLOATERS!

SkyVision Center's Holiday Time 2012 - Were You Naughty or Nice?

We love the holidays here at SkyVision!

 Dr. White starts with his much awaited holiday bowtie collection!   

                                      

                                        Today's tie is very dashing Dr. White!  

As you enter SkyVision, Santa looks to find your wish on his list of gifts he needs to get.  

Were you naughty or nice? 

  

Coming or going through SkyVision you are reminded of the holiday greetings  . . . . .

we wish for each and every one of you!

  

Happy Holidays from the staff at SkyVision!