eyes

[applicant2002]

I have a question about eyes. Do the same genes control both eyes, or is it very likely that someone will have two different prescriptions for each eye?

For example, if someone sees almost perfectly in one eye with a little bit of astigmatism and slightly hyperopic, but the other eye is much worse with astigmatism with a considerable degree of myopia. My question is this: is it likely that that was genetically endowed? I notice myself looking more with my ?good? eye, and sometimes tilting my head towards it to look straight.

I have read that they refractive power of the eye will not develop if you don?t use those muscles too much. So theoretically the cause of my poor vision in one eye could be my tendency to use the other eye more. It could also work the other way around though, and that is what I am trying to figure out. Is it likely (are there a lot of people with drastically different vision in both eyes?

If not, and if it is likely that my weak eye is weak because of lack of use, how can I strengthen it?

Thanks for reading and thank you for all your answers.

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[rpames]

I'm not quite sure of the genetic implication and the developmental aspect of ocular development and progression, but I will try and answer what I can.

It is much more common for a person's eyes to have fairly similar Rxs in both eyes. It is not very common for a person to have the exact same Rx in both eyes, but it is usually within a diopter. If someone is hyperopic in the left and myopic in the right, it causes problems. Of course there is the not seeing well in both eyes, but when correct with glasses or contacts there is still a problem The main problem is the size difference in image perseption. One eye will see the image larger than the other. When this happens, the brain can not fuse the two images together, so it basically shuts off one of the eyes. You basically become mono-vision.

With the the Lt eye hyperopic, you shut the Rt off when looking far away, and you shut the Lt off when reading. Unfortunatly there is nothing short of surgery that can help fix this. Lasik is the best option in that it will bring both eyes back to zero. But the odds are your eyes will do the same thing as time passes.

If the difference between the eyes is not to drasitc, it can be partially corrected with glasses or contacts. Basically if you do not get a set of corrective lenses (glasses or contacts), the problem will get worse. You need to get the "weak" eye back to a point where your brain will at least try and use it, or you will loss it. The more you shy away from that eye the weaker it will get, and the less chance you will have of getting it back. It is very important to get a set of glasses on that eye. Besides the stated loss of the eye, this could lead to headaches. With two good eyes, we switch back and forth between them. We use one, and then use the other while first one rests. By using one eye all the time, it gets tired and you may not be able to read or even focus for long periods or time.

There are no real exercises you can do to prevent the changes. But in the long run, this is not totally terrible. You may be able to avoid bifocals! Many people artificially create what you have natuarlly. People will get a reading Rx in one eye and a distance Rx in the other. This way they can drive with one eye and read with the other. They do this with contact and even lasik.

Lasik can be great, but it can not let someone with bifocals walk away without them. They can correct for distance or near vision, not both. In these cases they will do what I said above, one eye for reading, and the other for driving. If they do not do this, the patient has to use a reading set of glasses.

I hope I helped alittle. If I got anything wrong, please let me know.

 

[rpames]

Wow, one can never keep-up with new technology. I was reading some medical news just now and found a treatment for presbiopic patients. You know how I said we could not correct near and far vision on the same eye...well, it looks like we will be able to soon. Read this:

Laser May Eliminate Need for Reading Glasses

NEW LASER MAY ELIMINATE NEED FOR READING GLASSES IN OLDER ADULTS

Weill Cornell Medical Center First In NYC-Area to Offer Treatment

Patients are Currently Being Enrolled For Study; Early Results Promising

New York, NY (February 14, 2003) -- A new laser technology has shown promising early results for the reversal of presbyopia, a progressive stiffening of the eye's lens that occurs with aging and compromises an individual's near vision, or the ability to read without glasses. NewYork-Presbyterian Hospital Weill Cornell Medical Center, first in the New York City-area to offer the new procedure, is currently seeking participants

for a Phase II clinical trial of the innovative technology, called OptivisionTM.


"Everyone over the age of 50 could potentially benefit from this new high-tech treatment," said Dr. Sandra Belmont, Principal Investigator of the new trial and Associate Professor of Clinical Ophthalmology at Weill Cornell Medical College. "The procedure, which takes only thirty minutes per eye, involves eight tiny laser incisions in the sclera, or the white of the eye. This allows the lens to expand, and enables the eye to focus at different distances. Within an hour, patients are able to read without glasses."


Eligible participants include healthy men and women between the ages of 50 and 65 years, who have difficulty reading without glasses, and have not previously undergone eye surgery. Fifty patients will be enrolled through the NewYork-Presbyterian Weill Cornell study, which is expected to be completed in two years. The study will involve regular monitoring of patient's vision.


Early results are promising; in one case, after one month, a patient with 20/70 vision now has 20/20 vision. Also, trials outside the U.S. have indicated almost no regression after surgery, with more than 80 percent of patients reading without glasses post-operatively.


Until now, the only available treatment for presbyopia was so-called monovision correction, achieved either by wearing contact lenses or undergoing LASIK surgery. (The most common laser vision treatment, LASIK, treats the cornea to correct nearsightedness, farsightedness, and astigmatism.) Monovision correction, which corrects one eye for distance and the other for close vision, may decrease depth perception in some patients.


Dr. Sandra Belmont is also Director of the Corneal Service and Associate Attending Ophthalmologist at NewYork-Presbyterian Weill Cornell.


OptiVisionTM is manufactured by Surgilight, Inc., of Orlando, FL.


www.HealthNewsDigest.com

 

[cpw]

i don't know many people that will run right out to have eight slices put in their sclera. The thought of it gives me the creeps. But, I'm sure some said that about lasik a few years ago. There are also some advances soon in moldable crystalline lenses. Some of the professors at UHCO are working on it. That way you can have a lens that the ciliary muscles can control again to help you accomodate.

 

[rpames]

The new lens sound great! That would be a great improvement.

 

[OphthoBean]

If I got anything wrong, please let me know.

Most of this is inaccurate if not completely wrong. Where to start...? There is just too much to make a dent in it before the sun rises.

 

[cpw]

Originally posted by OphthoBean
Most of this is inaccurate if not completely wrong. Where to start...? There is just too much to make a dent in it before the sun rises.

could you PLEASE be more full of yourself.

 

[rpames]

I'm pretty sure what I stated was right, but please inform me of any errors.

 

[OphthoBean]

First of all, no, I can't be more full of myself, it actually was late and past my bedtime and there was no possible way to go over genetics, ocular development, optics, and presbyopia in a 5 minute post.

Second of all, a forum for pre-professionals and professionals in training is not an appropriate forum for dispensing of medical advice.

The original poster has specific questions and concerns about his anisometropia and a head tilt, but offers vague history and symptomatology. Instead of writing a dangerous manifesto about vision correction, this poster should have been told to present in person to an eyecare professional to address his concerns. For all we know he is no where near presbyopic age, he could be amblyopic due to anisometropia or strabismus, he could have a CNIV palsy, etc.... If he happens to have a simple refractive error and you tell him to get glasses and he sees better, great, you are a hero. If there is other pathology, say he is amblyopic and over age 8 or so, glasses would solve nothing and you have done a disservice with incorrect information.

My point is that he could have any number of problems, some correctable, some irreversible, and it is dangerous and unwise to offer treatment advice online for an undiagnosed problem. I would think we all know better than to diagnose ocular disease without a proper history and exam.

I did not intend to come off as confrontational, but looking at my post I see how it could look that way. For this you have my apology.

So, to the original poster: Please find a local optometrist or ophthalmologist to visit to discuss what could be anything from a minor problem to one needing more more intensive intervention.

 

[rpames]

Ok, you are right, I perhaps should have put a disclaimer reminding everyone that anything posted on the internet is not to be considered absolutely true and you should always seek a "live" medical professional. May I just say...DAHHHHH!!! Christ Almighty, must we explain every little obvious thing.

Perhaps my logic was flawed by me using Occam?s Razor; ?With all things being equal, the simplest answer is most likely the correct one.?

Most of this is inaccurate if not completely wrong.

I have a query, what was wrong with what I said? You never mentioned my errors. Let us say I was correct in guessing the poster had a simple problem such as just being too hyperopic in one eye and too myopic in the other, was my answer ?completely wrong? ? If it was as simple as my meager mind theorized, I think I did a pretty darn good job for a lowly undergraduate student.

Just to show that I can use large words too, what I was presuming was the poster had anisometropia. When I referred to the need of a correction, I was alluding to the concern of the ?weak? eye going amblyopic or, I believe in some cases, the brain may even induce a strabismus to help the individual ignore that eye. This strabismus could be intermittent and the cause of the tilt in his head. (I would like to see a cyclorotational Strabismus. Has anyone seen this?)

I did not think about CNIV palsy because the poster did not mention a down and in movement of the eye. I would think this would have been noticeable do to the vertical diplopia which would be even more pronounced when looking down.

I did not even say the post was presbyopic. I just made some side note about the implication of having minor anismetropic as a presbyopic individual.

Sorry for the second manifesto, I but I just can?t stop myself. I?m off to my shack in the wood.

 

[applicant2002]

Hi again.

First, thank you all for your time to answer my questions, especially rpames. i really appreciate the time and effort.

Let me clarify some points:

I wear glasses (ever since I was 8 or 9 or so)
I can see clearly from both eyes out of those glasses.

No i don't have CN VII palsy

I've been to optometrists often at least 1 every 2 yrs or so.

All the optometrists always seem surprised to notice the great difference, but nobody ever said anything about it.
I'm not trying to get free advice, just some information and I guess I could look it up, but I wouldn't know where to start, and I thought that you all would be good sources.

My question was more of a theoritical question. I've been learning about the eye and my theories about my eyes is this. Are these possible or even likely?

1. My right eye (the really myopic one) just grew a little faster when i was little but because i got galsses then, my eye adjusted and made it a permanent dysfunction, instead of just resolving when I got physically bigger.

2. For some reason, I started using my left eye more, and so it kind of got used to seeing, so my right eye got "lazy" (although not to the extent of a "real" lazy eye).

3. My right eye was kind of lazy, but it was never diagnosed, so it never developed visual acuity.

If 2 or 3 is the case, then could I develop the visual acuity by wearing eye patches or something?

BTW, it's not a drastic tilt, it's subtle. For example I am typing this and I feel my left eye looking at it more. If I close my left eye, everyting looks kind of farther away(smaller). If I close my right eye, everything looks normal as if I was looking with both eyes, which means that when I am looking with both eyes i am predominantly using my left eye.

I still use my left eye predominantly even though I wear glasses. I don't know why that is. Maybe that supports theory #2?

Thank you for all responses.

BTW, can you define all those big words?

 

[drbizzaro]

zonular surgery can also help