Junior wrote:
I just got glasses for the first time 2 weeks ago and I was told to wear the full time even though my prescription is week in my right eye is -0.50 myopia then my astigmatism is -0.75 and the same for my left eye. I have been wearing them all the time and since then every time I take them off I find it hard to see at all distances is that normal? Should I be wearing my glasses full time? The doctor even said I should wear them even when I’m on the computer, my lenses are single vision

ANSWER

Dear Junior.

Thanks for your interest. Your have a low level of visual correction. What disturbs the most in your case is the presence of astigmatism that can distort the image at far and at near. An astigmatic eye sees skewed what is plane and planed what is skewed. Not efficient in a real-world situation. Once corrected, it takes a few days for the brain to “reinterpret” that a plane surface is plane and a skewed object is really skewed. If you withdraw the correction, the brain can not interpret what you see anymore. This is why the objects remain blurred.

I agree with the recommendation of your optometrist to wear your prescription on a full time basis. This will alleviate vision distorsion and eliminates the risk to develop ocular fatigue, migraine or other asthenopic problems. Consider contact lenses as another way to correct your vision. More convenient, they can make your vision even better.

Good luck,
Langis Michaud, OD, MSc, FAAO
Associate Professor, U de Montréal

Thornton  wrote:
I have astigmatism in both eyes. I can see clearly with my glasses, but rectangles, such as my computer monitor, look skewed (longer on the right side). With enough adjustments to PD, optical center, and lens/frame position, I was able to get the skewing to a minimum that I don’t notice (most of the time).

I recently tried rigid gas perms, which my optometrist said should correct the astigmatism better than the glasses, but there was more skewing. It was different, though; the bottoms of rectangles are narrower than the top.

My prescription is:

OD: -2.25, -2.90, 35
OS: -3.75, -1.75, 140

First, what causes the skewing? Second, are there tests that can be done to determine a prescription for me that give clear vision without rectangular objects being skewed?

ANSWER

Dear Thornton

This is an interesting question. In order to answer it properly we have first to explain what astigmatism is. It comes from an oval-shaped eye - either on the cornea (transparent surface in front of the color of the eye) or on the internal lens (crystalline) that helps to focus at far and at near. One of these structures, or both, are oval-shaped meaning that one of their curve is more prononced (steeper) than the other one. In lay terms, we describe it as a “football” eye instead of a “volleyball” eye. Once the light hits such an oval structure it is distorted. Through an astigmatic eye, if you look at a cross, it will be skewed (depending on the axis) and one arm will be clearer than the other one. In your case, your axis is 35 and 140. This is called oblique astigmatism. The skew from your astigmatism distorts the image at angles. On a clock position, the cross you would see would be skewed with one arm at 2 o’clock and the other one at 10.

In glasses, astigmatism could be well corrected but as soon as you look through the peripheries of the glasses (outside of the center) you add to your astigmatism what is called optical aberrations. This is due to the shape and the optical properties of the glasses. The more prononced the astigmatism is, the more you will get distortion outside ofthe center of the glasses. High myopes patients share the same problem.

This is why contact lenses are preferred to correct astigmatism. When they are fitted properly, the lens follows the eye and eliminated the peripheral distortion. THe vision is sharper and clearer.

In your case, modern soft contact lenses (in silicone hydrogels - to preserve ocular health) are able to correct properly the astigmatism. Problems in the past with soft lenses include bad vision and discomfort mainly due to the fact that the lenses were not stable on the eye. Modern toric contact lenses can correct vision and they are really stable. I would recommend you Acuvue Oasys for astigmatism or Cooper’s Biofinity Toric. THese are the most comfortable and stable Si-Hy lenses in the market.

For gas perm lenses, your optometrist is partly right. In the past, they were considered a better option based on the fact that soft lenses were not stable. With Oasys and Biofinity this is not true anymore. However, for some patients, especially hyperopes astigmat patients (this is not your case) gas perm rigid lenses are preferable due to higher oxygen transmission.

I don’t know if you got spherical contact lenses or toric contact lenses. Unfortunately, some practitioners tend to prescribe spherical lenses on toric corneas. This is not appropriate in soft lenses and acceptable in rigid lenses just for small amount of astigmatism, which is not the case. Another way to prescribe rigid lenses is to design a back toric lens- This is a popular method but, considering your right eye, probably not the good one. This design is not stable and can induce secondary astigmatism on highly toric cornea (like yours). THis secondary astigmatism can cause the distorsion you see through your contact lenses.

In your case, I would strongly recommend the use of a bi-toric gas permeable rigid contact lens. This is easy to design through the Mandell-Moore formula and available everywhere. This design matches the internal curves of the lens to the ones of your eye, like a mold, and the vision is fully compensated with the proprer addition of a toric correction in front of the lens. COnsequently, both surfaces are toric and the lens is named a bi-toric lens. This is the most stable on the eye and provides sharp vision. The only other thing to determine is the diameter of the lens. Based on your corneal diameter and your pupil size, your optometrist will determine the appropriate contact lens size to alleviate  glare, halos and other aberrations possible with a smaller lens.

In summary, contact lenses are a great option for you but I feel that you did not have the proper ones prescribed for you. Consult your optometrist again and explain your problems. He/she will be able to help you. Anytime he can contact me with the details of your prescription in order to discuss it over the phone or by email. It should not be difficult to achieve a favorable outcome with all the options that we have in hand nowadays.

Good Luck,
Langis Michaud, OD, MSc, FAAO
Associate Professor, U de Montréal

Amy wrote:
I’m wondering if a person’s eyes (like their ears) can have anything to do with motion sickness.

I am 32, and my left eye is -6, right eye -3.75.  Because I also have a severe astigmatism, my lenses are quite different and throw me off balance at times.  My equilibrium is a bit off, and I find that my depth perception is also affected.  I get car sick and air sick, and it has made my love for travelling absolutely miserable.

I had an appointment with my eye doctor today as my vision has been steadily declining over the past few years, but this is the one question I forgot to ask.  I think my doctor was more bewildered at why my vision is going downhill so fast at my age more than anything else.  My topography scans have all been normal over the past 2 years, and today I had my first A scan, and was told that my eyes are “long”.  We’ll see how different that looks in a year (if my prescription lasts that long).  No glaucoma, diabetes or anything else, (I am pretty healthy except for scoliosis) yet my prescriptions are changing every 9 months.

I am on allergy medications; I use Benzaclin, take a daily vitamin, and an occasional Advil or Zantac. My second question is: are there any known medications (I’m NOT on antidepressants) that have a side effect of vision loss?  I’m trying to find a link but maybe there isn’t one?

ANSWER

Dear Amy

Due to the difference in your prescription of each eye this might be throwing you off balance.  It is unusual that your eyes are changing so much at 32 years.   It is possible but unlikely that your problems are due to the medications.  Your eyes are long because you are myopic, so the eye is stretched in comparison to the normal eye; this gives you a minus prescription.  Further investigation of your eye condition may be required.  Please discuss your issues with your optometrist in order to address your concerns.

Jennifer wrote:
Hi,

I recently got my eyes check, and my optometrist told me my astigmatism got better. Do I need to change the prescription of my contact lenses or is it okay to leave it?

ANSWER

Dear Jennifer:
Without a lot more information about your prescription, the type of lens you are wearing, your wearing habits etc., I am unable to advise you. You need to see your optometrist to have your questions answered. If your optometrist supplies you with your contact lenses, then he/she would make any necessary adjustments to your contact lens prescription that you require.

Hope this is helpful.
Dr. Smit

Brittany wrote:
well I’ve been living with astigmatism since I’ve been in the third grade until about a year ago (I’m 24 now) my optometrist told me I didn’t have astigmatism anymore, that it was farsightedness that was plaguing me now. I’ve only seen her twice in the past could this of really happened or could I have been miss-diagnosed all these years?

ANSWER

Dear Brittany:
By far the majority of patients that I see in my practice have some astigmatism. Some patients have a lot and that is their “primary” diagnosis, but most patients who we diagnose as “nearsighted” or “farsighted” also have some astigmatism present. Sometimes there is only a very small “negligible” amount of astigmatism present, and occasionally we find no astigmatism at all. While most people who have a significant amount of astigmatism at an early age tend to have astigmatism throughout their whole lives, I have several patients in my practice who had significant astigmatism as young children, but grew out of it in their later years. So, yes, it could have happened.

Cheers,
Dr. Smit

Sherry wrote:
I’m a long time gas perm contact lens wearer. I started in hard contact lenses in 1979 and then moved to RGP lenses in 1988. I see very well with them 20/20.
I am +5 or so in both eyes and have an astigmatism that keeps me from wearing soft lenses.

I recently got a new pair of RGP lenses after 8-10 hours they feel gritty. No amount of artificial tears help. When I remove the lens, there is a white film on the lenses. Keep in mind I use Refresh tears throughout the day. I did not have this problem with my old pair; I could wear them for 16 hours if I needed to. I replace my RGP lenses yearly and clean with Optimum Lobob as well as use an enzyme drops twice a week with a Boston solution. I make sure all the Boston is off when I use the solution with their enzyme (my only choice since enzyme tablets are off the market).

Should I have the lenses remade with a different material? Any suggestions on brands that could be used?

I am very frustrated. I don’t like taking my lenses out to clean them, especially when I am in a public place.

ANSWER

Dear Sherry,
Since you started wearing contact lenses in 1979, I presume you are in your mid-forties or above. It is not uncommon to experience a decline in the ability to keep lenses (rigid or soft) moisturized at this age. There are a number of contact lens re-wetting products available, but there is no single drop that satisfies every patient. You might try using another product such as “Blink” which is designed to be used with both rigid and soft lenses. It has a fairly good track record in our practice.

However, since your symptoms seemed to have started abruptly when you got new lenses, it is possible, as you have suggested, that the new lens material is contributing to your discomfort. It might be helpful if you could contact the practitioner that supplied you with your previous lenses. He or she should be able to determine what material it was that you were wearing successfully, and it may we worth your while to have a new pair made of this same material, if it still available. There are number of rigid gas permeable materials available, but again, there is no single product that satisfies every patient. There are number of different Boston fluoro silicone acrylate lens materials that have good reputations for “wettability”. I would suggest that you discuss your options with your optometrist.

You also say that you are unable to wear soft contact lenses because of your astigmatism. While that was probably true in 1979 when you first started wearing lenses, there is now a fairly broad range of astigmatism correcting soft contact lenses available. If your RGP comfort issues cannot be solved, you may want to revisit the possibility of wearing soft contact lenses.

Hope this is helpful.
Dr. Smit

George wrote:
Hi. I’m 26. I have strong astigmatism in one eye and a lot of near-sightedness but little astigmatism in the other. One optometrist has told me, jokingly, that it seems as though my eyes are from two different people. Uncorrected, my left eye is about 20/50, my right eye about 20/100. Supposedly the difference comes from retinal scarring when I was young, but I’ve never been diagnosed with amblyopia.

Here’s my problem: I recently got a pair of glasses from my ophthalmologist that drive me nuts. There’s a feeling of constant tenseness, and I have a hard time maintaining an awareness of things with my peripheral vision, and when I go into busy interior areas, such as a grocery store, I become very confused. My concentration suffers, for instance, and I jarringly lose track of thoughts whenever I shift my eyes to refocus. Reading is also difficult. I told all of these things to the doctor when I went in for a recheck. He said I would get used to the new prescription, and I have not.

I noticed that that the image I’m getting on the left side is squat (from the astigmatism correction) and the right eye is tall and skinny and distorts heavily toward the left and right edges. When I insisted on the difficulty with this prescription, suggesting that the squatness on the left could be causing my discomfort, my ophthalmologist said that he had indeed added an additional dioptre of astigmatism correction, and he could remove it if I wanted, at the cost of sharpness.

There are three things keeping me from having confidence in that solution: 1) It originally came from ME and not from my doctor, who other than shine a light in my eyes performed no tests for binocularity or refractive difference, so I suspect that he’s not properly examining my eyes, merely relying on my last prescription. 2) For about the 8 months leading up to my current prescription, I did not use glasses at all. I performed a lot of high-stress public-speaking related tasks and got very used to squinting and functioning without glasses. 3) I have a very old prescription, from a different doctor, that causes none of the symptoms I described above and is much, much easier to read with.

My question is this: I have no insurance so visits can be expensive. I see a few courses of action: 1) return to my ophthalmologist and request a comprehensive eye exam, telling him about the old prescription and reiterating that I went without glasses for 8 months. 2) Get a comprehensive eye exam from somebody else, and if so, would it be better to go to an optometrist, an ophthalmologist, or an orthoptist?

Before I do anything at all, I’d also like to know what an optometrist thinks might be going on.

Thanks so much!

ANSWER

You mention not using your glasses for 8 months, and I hope this means that you do not drive. Changes in Astigmatism correction can cause the distortion that you are describing. I would suggest a new exam, and I would suggest that you see an Optometrist as these doctors are trained very thoroughly in the determination of the best possible and most comfortable lenses for your glasses.  Explain the problem to the new Optometrist and bring along all of your glasses.

Dr. Joan Hansen - Optometrist, CAO

Pajoe wrote:
I this new eyeglasses that I have for almost 4 days now. At first everything was like magnified and the floor looks elevated and when I watch the television the screen tends to look like a parallelogram and sometimes trapezoidal especially when I look from left to right. Vertical surfaces tend to lean away from me. Is this normal? The doctor said is because they are astigmatism glasses but, when I wear my old prescription glasses everything is normal (depths and shapes) but, the new ones are a little bit clearer. Is this normal? Please help. I paid a lot with prescription.

ANSWER

Dear Pajoe:
If your new glasses are a little bit clearer, then they are probably providing a more accurate correction for your astigmatism. The symptoms you are describing are very typical for someone adjusting to a new pair of glasses with a stronger astigmatism correction, especially if the orientation of the astigmatism correction is at an “oblique” axis – that is, not perfectly vertical or horizontal. I can sympathize with your concerns, as I have had many patients make the same observations in my office. Fortunately, humans tend to be very adaptive creatures, and most patients adapt to the change in visual perception over a period of a few weeks – some take a little longer. In time, most patients find the benefits of the improved visual clarity to be worth the initial adaptation period. Your symptoms should disappear over the next few weeks. However, if you find that things are not improving at all after a couple of weeks, you may wish to talk to your optometrist about providing you with a “compromise” prescription which has less astigmatism correction. It may make your adaptation easier, but you would likely have to accept a decrease in your visual acuity. In my experience, with a little perserverance most patient adapt to, and eventually prefer, the more accurate prescription.
Hang in there a bit longer.
Dr. Smit

Bob wrote:
Recently lost my right RGP bifocal contact lens.  Now live in new city with new OD.  He says he cannot produce suitable RGP bifocal due to increase in my astigmatism since my contacts were prescribed.  I asked about just replacing the lost contact - exactly.  He said that risks the health of my eye and cornea.  Is that correct?  Because that is what I would be doing if I had not lost the contact.

Bob

ANSWER

Hello Bob,
Without examining your eyes and knowing exactly how much astigmatism increase there has been, it’s very difficult for me to say whether your old contact lens would “get you by”.  However, there are bifocal RGP lenses available specifically for astigmatic patients.  These lenses are more costly than the standard bifocal RGPs and can be tricky to transition to, but may be what you need at this point.  I suggest enquiring to your new optometrist about your candidacy for a toric bifocal RGP.

Good luck!
Dr. Donati

Sadia wrote:

Hi,

I have astigmatism of -1.00 in both eyes but do not need any sphere correction. I would like to get the freshlook toric colourblends however, more toric lenses I am told are made in quarters. So for the contacts I would like they only have -0.75 or -1.25.

My question is should I be going with -0.75 or -1.25?

Thanks

ANSWER

Dear Sadia:

This is a question that you should ask you optometrist because he/she would be most familiar with your refractive error and should be the one choosing/prescribing your lens correction. In normal circumstances, the patient does not choose the prescription they wear – that is left up to the prescribing doctor. In my practice I might tend to use the lower power astigmatism correction because if the lens rotates away from its ideal fitting position, it will have a less noticeable affect on your vision. However, there are many factors that must be taken into account. Check with your optometrist.

Dr. Smit