This is not an issue in the "fun" category, but I thought a little bit of
consumer information might be useful. This information only applies to infantile
strabismus in adults. By this contradiction in terms I mean strabismus aquired before 6
moths of age, with which, assuming you're older than 10 by the time you read this, you're
It is not known what causes strabismus. It's effects on the development of the visual
systems in the brain are known to a certain extent.These effects are permanent and cannot
be fixed (lots of "behavioral" optometrists will disagree with me on this one!).
It requires a very elaborate system consisting of 12 extra-ocular muscles, several
different oculomotor systems in the brain, and feedback from visual input, to keep them
pointing in the same direction all the time - no matter how you move your eyes. In adult
strabismus some or all of these systems have some defect or another ("Does this mean
I'm brain damaged?" No! Your hardware is OK, it's just a few software bugs,
and nobody knows how the heck to upload a new release - yet.) So chances are that if your
eyes are aligned your software won't be able to handle it. Might even give you a horror
diplopia. Unless you already have a horror diplopia or the deviation is "cosmetically
conspicuous" it is not worth the trouble to correct it. The simplest way to check
whether or not your particular software will accept a corrected positioning of the eyes is
using prisms. That way the alignment is simulated by deviating the path of the incoming
light. Very simple!
In general, it is very important to get the best possible correction of any refractive
error - especially for the better eye. This can be pretty hard because the average
standard acuity test involves totally occluding each eye in turn, which can make latent
nystagmus a bother. In that case apply one of the "blurring" tricks described
..Are prisms fun?
||This depends on the required strength. For example, a turned-in eye requires a prism
with the thin edge towards the nose. This moves the things you see towards the nose, but
also for the people who look at you, so your eye appears to be even more displaced
inwards. ("These new glasses of yours only make it worse!" they'll say).
This is a disadvantage of a prism made of glass (or plastic). Another type of prism is the
Fresnel type - the "lighthouse" sortof lens, manufactured as a membrane. It can
be stuck on regular glasses, does the same as any other prism, and people only see weird
thin lines across your eyeglasses. Fresnel "stick-on" prisms have bad optical
properties though. Just like glass prisms have in the higher strengths. Up to 6 prism
diopters you don't really notice the things (either you or an observer), and they can
highly effective, but if you happen to need 30 prism diopters it's a whole other matter -
aside from distorting the image, everything gets colored edges. Prisms can produce great
rainbows, after all.
..Is surgery fun?
Probably never, but it is not a big deal either. It's not like they have to take out whole eyeballs and sew 'm back in. Chances
are you'll look like somebody hit you in the eye ("Gee, you've been in a pub
fight?") for a week or so. Psychologically it can be rather hard to accept having
someone poking a knife around one or both Windows To The Soul, especially for the innocent
bystanders like family and friends ("Oh my, eye surgery, how gross! Yuck!). It
is said to be no worse than having some dental work done, though. Some people are very
nauseous afterwards - the technical reason behind this, is that pulling and tugging at
extraocular muscles indirectly sets off the emesis center in the brain. This effect is
much less pronouced when local anesthesia is applied, instead of general. When it comes to
cost-effectiveness.. surgery is covered by insureance, while mostly glasses with prisms
($$$!) are (mostly) not (In the Netherlands, that is).
A question I received a couple of times is: what do you actually experience and see
during strabismus surgery with local anesthesia, and in order to have a properly
researched web page I had a close friend try it. :-) It was, reportedly, more fun than the
dentist, reminding a bit of "A Clockwork Orange", but actually not very special.
Vague silhouets of somebodies hands, blurred lights, some sensation of somebody fumbling
around and leaning on your nose, worst part being the separation from your face and the
self-adhesive draping sheets stuck to it.
..Are patching or "Vision Training exercises" useful?
Thought I'd include this one because it is quite a "frequently asked question".
Whatever you do, don't EVER patch your good eye. Just don't. Amblyopia is there to
stay anyway, and you won't gain anything besides perhaps terrible diplopia.
Patching is for infants! It will NOT make you "see" the Magic Eye pictures, it
is totally useless and certainly not harmless either. Don't even occlude a small part of
the good eye (there is this urban legend saying your eyes will "learn how to work
together" when you stick a small round dot on the middle of one eyeglass and walk
around like that for some weeks) - the results are about as disastrous as any other ill
advised patching "therapy". I hope this is clear! Somehow it is part of folklore
to associate strabismus with patching, but again, patching the good eye is for kids.
"Vision Therapy" (see for example The Stereo Vision Project )
can be a lot of things; "natural vision", "curing amblyopia",
"eye tracking excercises", "3D perception training" - there is
probably no harm in it as long as you get this training from someone who is qualified - an
optometrist for instance. There is evidence Vision Training works - but if it works for all
types of strabismus is not clear. Beware of quacks, there are some businesses out there
claiming they can fix your debililtating diplopia, nystagmus, glaucoma, myopia and improve
your sense of well-being all in one go, with some unheard-of miracle cure. If these claims
were true they'd have won a Nobel prize by now, so this is nothing but clever marketing.
..And if all else fails?
Notice: don't apply any form of patching without getting medical advice first.
When we're talking about unacceptable diplopia, occlusion or "blurring" of the
amblyopic (or otherwise least useful eye) is an option. Best occluding device is the good
old sailor's patch. Less conspicuous are occlusive contact lenses. There are soft and hard
lenses with a black pupil, and lenses with a painted iris and pupil. The ones with the
painted iris and pupil are the best choice, but have to be carefully matched with the
fellow eye, and are quite expensive. The ones with just a black pupil come in different
pupil sizes, and you have to buy one with a larger diameter than your pupil dilates at
night, otherwise it'll "leak" all around the edges. During the daytime this
makes the difference in pupil size between the two eyes very visible ("Is your left
brain on dope or something?"). My experience is limited to the soft lens with painted
on pupil, and it wasn't a good one - to start with the thing was more dark grey than
black, and in the course of just a week of occasional use it discolored to a transparent
blue, and so did a replacement lens, even after having switched to some high tech kind of
very expensive cleaning solution. Not just your pupil diameter is an important parameter,
also if you have eccentric fixation, it is like the lens is never properly centered,
you'll always be looking "around a corner". Furthermore, if you happen to have
latent nystagmus, occluding one eye makes that very noticable, it may even be more
irritating than diplopia.
"Blurring" the input to one eye can be a viable alternative for some - the
advantage being it mostly doesn't provoke nystagmus in the fellow eye. For a blurring
device you can use a high power plus contact lens (the actual power needed depends on if
and what prescription glasses/contacts you normally wear), a "frosted" eye glass
(very ugly), Scotch magic tape on your normal glasses (also unsightly, but highly
cost-effective), or a pair of high strength reading glasses (the el cheapo ones from the
gas station or drugstore) from which you remove one glass; these can be worn over your
regular glasses if needed - if you don't mind looking rather ridiculous. And of course,
you can always learn to live with it! ..barf.. (oops, sorry).. or write a WEB page
A naggingsubconscious begs me to correct this subtle lie: it may be no big deal for
most, but lots of people (after strabismus surgery with general anesthesia) suffer
from PONV (Post Operative Nausea and Vomiting) A GASNet source describes PONV in a poetic
way as: "Nausea is the uncomfortable sensation of an impending episode of
vomiting. It is often associated with prodromal symptoms such as salivation, swallowing,
pallor and tachycardia. Vomiting is a complicated process [...] The following types of
surgery have been found to correlate with a higher incidence of PONV: Laparoscopic
(especially gynecological), strabismus, [...]" After strabismus surgery
with local anesthesia PONV is very rare.
Speaking about the general anesthesia again, and without any anti-emetic medication, PONV
occurs in about 85% of cases, with the most expensive kind of medication (Ondansetron) in
about 6%, and with Droperidol in about 20% of cases. Droperidol is the most cost-effective
choice for hospitals and most used. However, being one of those 20% of cases, is just