Each stereo view consists of two images, one for each eye. Free viewing is the technique that will allow you to direct each of these images separately and simultaneously into each eye without using a stereoscope.  If you have presbyopia and need reading glasses, put them on.

The image to free fuse looks like this:

Cross your eyes, so that the pair of images will double to four, and it may be out of focus. At some point, the two pairs of images you are seeing will begin to overlap.  Another way to accomplish this is to use a pencil or fingertip laid on the paper at the black bar.  Bring the pencil forward while focusing on the tip keeping it clear.  The background images will blur:

The part of the image in color indicates the beginning of an overlapping view.  That area of overlap is where you will fuse the left and right images of the pair. Continue to bring your pencil or fingertip towards you until the fusion effect (while still blurry) looks like below:

At this stage below, your eyes are crossed just the right amount (convergence) but the focus is off (accommodation). 

You must dissociate the focus (accommodation) from the convergence while keeping the center image fused together.  Try tracing the details such as blood vessels or the rim of the optic nerve head to help you gain a clear focus.  Continue to keep your eyes crossed.  In a few moments your visual system will redirect your eyes to focus on these details without uncrossing.  When you have achieved it, you should be able to perceive the 3 dimensional depth of this optic nerve head cup.

This technique can create eyestrain as accommodation and convergence are not designed to work at differing distances.  Some people cannot simply achieve the stereopsis effect.  If you have amblyopia, strabismus, are monocular or suppress one eye then you won’t be able to see in 3D.

Stereo viewers with variable prism greatly assist fusing these images.  With practice this free fusion technique develops more quickly.

The trouble begins with the heel of their foot catching the back side of the footrest.  Theres a little ledge under the pivot bar that the heel can push.  The platform pivots forward so that if crash lands behind them in with a loud metallic clunk after the first step away.

I invented a fix that prevents this unwanted surprise.  The chairs we use are the Topcon OC-20T.

A Magnetic Solution

After experimentation I found that N40 magnets from a business called “MagnetMan” on Amazon creates the perfect blend of attraction without requiring too much force to disengage.  These are strong neodynium magnets and you will need to take caution with this size or larger.  Skin caught in between two magnets can cause a blood blister or a bruise due to the strong magnetic forces attracting to each other.

The footrest on my chair is attached by a wingnut.  The back side has slots to allow the upholstery seam to attach.

Slip a magnet into the wooden slot and continuing through the padding to reach the backside of the upholstery.

You can use another magnet to guide it to where it’s best.

After positioning the 2 chair magnets behind the upholstery, determining where to place the magnets for the footrest is easy.  They will self center.  Keeping the placement high like shown may offer the best leverage  for keeping the footrest in place when raised.

The footrest is made of aluminum so the magnets won’t stay by themselves when when the footrest is lowered.  A dab of double-sided sticky foam tape holds them in placed when deployed.

Their may still be some instances of “kerbangs” but my solution should prevent most of them now.

Hot temperatures decrease the darkening effect.  As an example, we took a glass photochromic lens called Photogrey Thin and Dark ® (link).  This lens is the darkest glass photochromic we are aware and gets down to 14% transmittance – a good sunglass grade.  This means that 86% of the visible light is filtered.

We measured the lens at 40 degrees F after a 3 minute exposure on a clear sunny day.  The lens performed as expected (see illustration – lower white graph).  We next measured the same lens at 100 degrees after a 3 minute exposure.  The transmittance only reached 54% (upper grey graph).  We used our Humphrey Instruments automated lensometer which has a spectrometer to measure the absorbance of light in the visual and UV range.

Hot lenses transmit more light (top) than cool lenses (bottom)

All photochromic lenses exhibit this behavior called temperature dependency.  The process is most efficient for skiers on snowfields than sunbathers on a beach on a hot sunny day.

There are dozens of vendors and we welcome you to comparison shop.   This review is focused on Amazon.com as it has a vast array of products that can quickly be searched.   Search for the items highlighted in bold to survey all the products.

Swing Arm Lamp  

These lamps can be swung in position to place the best light on your needs.  We recommending over the shoulder and behind position to offer the best light free from glare.  Prices from $13 to over $60.

Magnifier Arm Lamp

These lamps can also be swung in position but offer built in magnification for hobbies such as sewing, tying lures or tiny tasks.  to place the best light on your needs.  We recommending over the shoulder and behind position to offer the best light free from glare.  Prices from $20 to over $180.

Kindle

A Kindle is a electronic book display device.  It’s display has a crispness that’s better than traditional liquid crystal technology as used in smartphones and display devices.  It’s very efficient in battery life which lasts up to one month on a charge.

A Kindle uses e-ink technology that presents the page in a pearlescent display that rivals freshly printed text.  It has the advantage however of changing size to your needs.

Daylight reading is ideal, better than any other display available.

This device comes in several configurations from as low as $79 basic models to ones that can download for free without an internet connection with a touchscreen and finally full color models.  I recommend the 3G versions as they offer the most care-free downloading and no subscription fee is required to get the downloaded book.

You can browse and purchase books from the reader without needing access to a computer.  There is an initial setup process and you will need to have a credit card on file with Amazon.com to enable purchases.  If this is confusing, a child or grandchild can easily set this up for you.

A Kindle DX ($379) is significantly larger with a magazine size display page and offers even better magnification potential with it’s larger screen.

This version is much more capable of handling the enlarged text needs and is recommended if your visual acuity is less than 20/50.  The regular Kindle has a challenge in reformating for a larger font that presents just a few words at a time requiring frequent clicks to advance a page.  The DX can reformat more efficiently for reading enlarged text due to it’s larger screen size.

Text to Speech feature can read the text aloud to you in an electronic voice.  This feature is dependent on each title’s publisher allowing it to be turned on.

Book prices for first edition bestsellers are usually $9.99.  Books published before 1923 and out of copyright are free resulting in 1.8 million selections.

Other ebook technologies exist such as the Apples iPad series, Sony’s Reader and Barnes & Noble’s Nook.   All of these can be reviewed hands on at their respective stores.  Sony’s are available in several chain stores.  This review is limited to the Kindle due to it’s market share, popularity and display quality.

What drew my attention is a mention that the light emits UV and blue wavelengths.  Eye doctors use cobalt blue filtes or blue / UV led’s with a fluorescent dye called fluorescein.  It glows fluorescent to help us spot scratches, ulcers, dry spots and other conditions on the cornea of the eye.

I decided to compare the sonic to a Bluminator, a handheld blue-light emitting gadget specifically designed for opthalmic use.  I painted a piece of paper with fluorescein dye from a standard test strip.

The bluminator on the left projects a more intense beam which overexposes the image a little bit.  The Sonic Screwdriver on the right did just as good a job at making the dye fluoresce.

So the Sonic Screwdriver could be considered  a cool gadget to help break down the fear factor of folks scared of the idea of fluorescein administration. Comments on the results such as “Weebly – Woobly, Timey – Wimey” are optional.

Oh and being the ultimate multipurpose science fiction gadget, this one includes a pen on the opposite end to write down my findings.  And technically, could it be written off as a business expense?  This isn’t an FDA approved device for medical use but it still reinforces that ”Sonics are cool…”

Your deductible for the year is $155 (2010).  This can vary each year.

Medicare Part B coverage applies for one pair of glasses following cataract surgery.

Your claim is filled as a Durable Medical Equipment Regional Carrier (DMERC) claim which is a different branch of Medicare than the processor used for office and surgical visits.

Standard Frames are covered up to the allowable of ($60.72 = 2010 allowed rate) : of this Medicare pays 80% after the deductible is met.  The covered amount can change every 3 months depending on Medicare funding and policy changes.

Deluxe Frames are frames that cost more than the Standard Frame coverage.  For example if a frame selected costs $80.00 then the deluxe frame fee would be ($80.00 – $60.72) = $19.28.  Medicare does not cover this portion of the amount and the patient is due this amount.  The jargon Medicare uses is that this item is “noncovered.”  Medicare gives you the freedom to choose any frame you desire that your eyewear provider can provide.  The Medicare deluxe frame policy allows patients to choose from any frame and have part of their Medicare coverage help defray the expense of these frames.

Lenses for a standard bifocal or a single vision lens is covered.  The covered amount varies based on the prescription strength.  Medicare pays 80% of this after the deductable is met.

Options such as trifocals, progressive / lineless multifocals and lens options such as tints, photochromatic (e.g Transitions, Photogrey Extra) are not covered.  Scratch resistant coatings, anti-reflection coatings, and special materials such as high-index or polycarbonate are not covered either.  A patient can opt to purchase these options at their expense.

If you have insurance that is supplemental to your Medicare (also known as Medigap), then your claim is usually automatically forwarded electronically for review and payment after Medicare processes the claim. They may cover the 20% of the costs that Medicare doesn’t cover.  They will not cover the “noncovered” expenses such as deluxe frames and lens options.

Future eyewear purchases are not covered after the first pair.  An exception to this rule is for people that did not receive an intraocular lens during their cataract surgery.  They however end up with heavy and thick lenses to wear for the rest of their life.  Over 99% of patients get intraocular lenses which avoids this inconvenience and offers more natural vision.

The specific policy by Medicare can be researched at:  https://questions.medicare.gov/app/answers/detail/a_id/840/~/what-is-the-medicare-coverage-for-eye-care-and-eyeglasses%3F

One recommendation is to use a server – client configuration. We started with a peer-to-peer network in 1992 and it’s time to make the change in preparation for electronic medical records.

One OfficeMate recommended server is a Dell PowerEdge T310

• Budget around $3500 nicely equipped with redundant power supply, faster RAM and a Raid 5 array of 3 HDD’s spinning at a supersonic 15,000 RPM. I think one could cut $400 or so with base equipment.
• Expect a build and transit time of up to 45 days until delivery.

OfficeMate recommends having a good IT guy set up your network. This is good advice if you don’t wish to go much of the hassle.

Tip Only for the Tech Savvy

If you are very experienced with your gear and willing to learn and explore the changes you need to make to go from a peer-to-peer to a server based environment, Paul Thurrott’s Supersite for Windows has a Windows 7 tip of the week that may save you money.
If you are the guy that sets up and fixes your own computer network, You are an IT guy. Microsoft has a program to invite IT folks to explore and experiment with their Microsoft’s software. Microsoft Technet Plus subscription can save $$$ for IT guys. Read his post to learn more. There is a discount at the bottom of the post you can take advantage until June 30, 2010.

Ophthalmic Optics can have some complicated equations.  We we see patients, there are times when a contact lens for astigmatism does not perform the way we predict.  We perform a measurement of the blur called an over-refraction and mathematically combine the result with the prescription to predict the next lens power that would work.  Before this utility was developed, we would have to do the math by hand or set up lenses together and use a machine called a lensometer to predict the next lens.  X-Cyl does the math for us so a doctor can just enter the variables and click on the answer.  It became wildly popular because it was faster, more accurate and free.  We wrote the software as a fun project and to help other doctors.

We wrote another program called ImageRx.  This calculator helps doctors design lenses that are equal in magnification.  Some prescriptions can generate headaches, eyestrain and double vision if the powers before each eye vary by too much.  To minimize the difference, we can vary the design of the lens such as the power, the fitting distance, the thickness and the curvature and refractive index to achieve an equal magnification.  This involved even more difficult calculations than what X-Cyl solves.  Before ImageRx, most doctors would would rely on nomograms.  ImageRx streamlines the design process and ensures mathematical accuracy to allow the eye care professional to try differing variables to solve their design challenge.

Both software have been updated to run on 32 or 64 bit operating systems.  They have been tested to run on Windows XP, Windows Vista and Windows 7.  Both are free and can be downloaded from our practice website.

Click on the icon to download.

X-Cyl Toric Crossed Cylinder Calculator
(version 1.20)

Updated for 32 or 64 bit Windows use, New tooltips and a clear button for faster, easier use.

ImageRx Anisekonic Lens Design Calculator
(version 1.20)

Updated for 32 or 64 bit Windows use, Calculate both lenses together now for easier use.

The epithelium doesn’t attach to the cornea after an injury.  It is loose and easily torn off.  Normally the epithelium should attach back to the cornea.  When this part of the eye is injured as from a scratch, an abrasion or a foreign body, the epithelium should grow back, seal down to the cornea and heal in a quick manner.  The epithelium of the cornea is one of the quickest healing tissues of the body in fact.  The presumably healed epithelium may cover the injury site and even appear normal  even with a microscopic view.

This condition is considered a dystrophy which means the tissue doesn’t work the way it should.  In this case, it doesn’t heal properly.

This can be a very frustrating condition for patients to endure.  They will report a sensation that a foreign body must still be present even though it was completely removed earlier.  This feeling of pain can be quite intense.  Extreme sensitivity to bright light can occur also when this problem is at it’s worst.  The patient swears something is still there and will even doubt that the doctor got the foreign body out – suspecting that another must be present or that the doctor must have missed something.

What is happening is that the epithelium moves with each blink.  The blink moves the loose epithelium, healed but not attached over the cornea. The epithelium rubs against raw nerve endings giving the sensation of a persistent foreign body with each blink.  Doubt about the health care provider’s competency may enter the patient’s mind especially if previous foreign bodies never produced such a problem.  ”This used to always get better,” or “I’ve had these injuries before and they healed up quite quickly in the past,” are common statements made by some.

Patients with Recurrent Corneal Erosion may often seek several opinions for their condition if they feel their current doctor does not appear to be efficiently healing their problem.  They can move from doctor to doctor in frustration.

RCE can be difficult to treat because it recurs.  A patient may carefully follow the correct treatment and suddenly lose all their success upon awakening one morning in pain – the epithelium rubbed off because of dryness of the eye causing the upper lid to adhere to the epithelium, ripping it when the eyes are first opened upon awakening.  The can occur over weeks – even months.

We find that the treatment needs to be customized to each patient.  A strategy for one patient may not necessarily work for another.  The treatments we try include:

Artificial tears: Many times a day.  Usually more is needed than the patient can attend.  One drop even once an hour or more often may be necessary.

Nighttime Ointment:  A bland ophthalmic ointment such as Lacrilube or Refresh PM instilled into the eye helps to prevent nighttime drying – which may be the most common reason for recurrence.

Hypertonic saline solution such as Muro 128 5% by Bausch and Lomb is a salt water drop that is 5 times more salty than our natural tears.  The extra salt of these drops can draw fluid trapped between the epithelium and the cornea to help the epithelium adhere to the cornea.  This drop may be needed several times a day and can sting upon instilling.  An hypertonic ointment at night may also be prescribed.

Bandage contact lenses may help by fitting tight against the cornea preventing the epithelium from moving.  This can allow the epithelium to stay still long enough to adhere.  For some people, a bandage contact lens may not work or seem to worsen the condition.  Studies have demonstrated that snug to tight fittting lenses can work best.  However a dry eye condition itself can make a lens uncomfortable.

Patching of the eye can be used if a bandage contact lens does not work.  Patching for some people  however may feel worse in a way similar that the bandage contact lens didn’t work.

Debridement is a procedure that removes the loosened epithelium.  A very light scuffing of the cornea may roughen the surface enough to allow the epithelium to grow back attached to the eye.

Anterior stromal puncture accompanied with debridement places a grid of tiny anchor points for the epithelium to attach to the cornea as it grows back.

Ocular comfort drops is a recent development.  A formulation of dilute anesthetic was recently discussed at an ocular disease conference.  Only 10% the strength of normal anesthetic, it’s weak enough to prevent toxic effects but allow patient comfort until healed.  This requires careful follow up to prevent complications and can only be used for a very select few conditions.  We have had excellent results with this option.

Restasis and Doxycycline are each considered experimental and off label treatments.  Restasis, an eyedrop,  is normally used for the treatment of dry eye.  Most folks with RCE have this problem anyway but it is theorized that the active ingrediant, (cyclosporine) may inhibit inflammatory factors that are involved in preventing the attachment of the epithelium back to the cornea.  Doxycycline, a capsule or tablet taken orally, has been shown to help patients with meibomian gland dysfunction in producing a normal sebaceous gland product.  It may also help inhibit the inflammatory factors the prevent efficient and normal tear production.

Time is a critical component of any treatment of this condition.  Days may run into weeks which run into months.  Setbacks may occur frequently requiring we begin from the beginning all over again.  The good news is that most patients do get the upper hand in successfully managing this condition and achieving a complete healing – although it took longer than they wish.

If you suffer from this condition you have our sincere empathy and understanding.  Persistence on your part will pay off in overcoming this often painful and nagging healing problem.  We dedicate ourselves to staying with you during thick and thin in helping you achieve a normal life.

This type of strabismus is called a left intermittent hypertropia.  There is a deviation of the left eye upward.

Most images show Lincoln’s eyes pointing straight which suggest the problem was not constant.

The image above is probably amongst the most well known of Lincoln portraits and also one which shows the problem.  His left eye is deviating upward slightly revealing more of the white part of his eye (the sclera) than in his right eye which is looking into the camera.

Another image illustrates the problem – perhaps more so.

Most other portraits of Lincoln show a head tilt to the right which could be a compensation for the relative weakness of an extraocular muscle producing the deviation.

Finally, what if one applied colorizing technology to Lincoln’s portrait?  You may come up with this result.  Coloring of an image taken by Alexander Gardner on February 5, 1865 and colorized by James Nance for the Abraham Lincoln Art Gallery.

His head tilts to his right slightly.  What impact does this image bring to you by adding color?