Caitlin wrote:
I wear contacts 95% of the time and I recently had my yearly check up. I found my vision less clear lately with my contacts, but my prescription hadn’t changed (-1.50 in both eyes). However, now when wearing my contacts, the left one is clearly not as sharp as the right. I’ve tried putting a new contact in, switching the contact, but nothing seems to help. It’s so annoying that I eventually give up after an hour and have to put my glasses on. What could be causing this? The obvious answer is that my left eye needs a stronger prescription, but my check up was only a month ago, and there was no change.

ANSWER

Caitlin,
Is your vision perfect with your glasses?  I would recommend returning to your optometrist to have them check this problem. Of course I haven’t examined your eyes, so it’s extremely hard to give you an answer, but I’ll give you some possibilities.  It’s possible if your glasses are perfect that you may have a small amount of astigmatism that your contact lenses are not correcting for and your glasses are.  A lot of times if there is a small amount of astigmatism it can be compensated for with regular contacts.  However if the astigmatism gets to a certain point, it will affect the vision and then a contact lens to correct astigmatism, called a toric contact lens may be required.  Astigmatism happens when the very front of your eye, the cornea is not perfectly spherical like a ball, but shaped more like a football. There are two different curvatures that need to be corrected, instead of only one.  Otherwise there could be an issue with your cornea or eyelid causing the problem.  Sometimes inflammation can develop in the cornea or eyelid, which will affect the quality of vision.  The main thing is to go back to your optometrist to make sure there is not an eye health issue which is causing your symptoms.

Dr. Doman

Timmy wrote:
Hi, i have a question regarding prescriptions for glasses and contacts. I understand you should not be using the degrees prescribed to you for glasses for buying contacts because contact lenses sits on your eyes directly as opposed to the glasses being a few inches away.
So my question is, would my eyes get worst or some sort of negative impact if I do wear contact lenses having the same degrees as my eye glasses?
the degrees for contacts should be slightly stronger or weaker? so if you wear contact lenses that are not exactly the same degree, what are the dangers of doing so? will it be merely less clear or will it make your eye sight worsen?

Thank you for your time

ANSWER

Hello Timmy,
Yes it is true that in most cases the prescription your optometrist gives you for your glasses is different than the one given for your contact  lenses.  Whether the contact lenses are stronger or weaker will depend on the prescription.  Wearing contact lenses that are the incorrect prescription (stronger or weaker) can cause symptoms of blur, headaches, dry, uncomfortable eyes and/or spasm of your focusing system.  Furthermore, if the lenses do not fit correctly, there are many other eye-health related problems that you would be at risk for.
When purchasing contact lenses from your optometrist, he/she will ensure that you have the correct strength and fit needed, and would be happy to give you a copy of that prescription for your records.

Thank you for your question. 
Dr. Donati

Stephanie wrote:
Three weeks ago I woke up with some crust around my eyes. I thought it was no big deal but it has been occurring ever since. I wear both contacts and glasses. Two weeks ago I noticed a dramatic decrease in the clarity of my vision. It has not worsened, but I just got my prescription changed in March and now I feel like I need a new one again. I also got new contacts with my updated prescription… about 3 months ago… The old one I wore were power: 2.25 and BC:8.5 in both eye’s and the new ones are power:2.5 in on and 3.00 by BC:9. Could the change in the BC be irritating my eyes and effecting the dramatic change in MY vision? And what about the crust around my eyes? I’m worried can you help?!

Thank you so much!

ANSWER

Dear Stephanie
If you are wearing soft contact lenses, dramatic changes in vision are not usually caused by a change in base curve (BC) such as you have described. Going from a BC 8.5 to a BC 8.9 lens means that the primary curve of the back surface of the lens is flatter on your new lenses than on your old lenses. If the material of the lens has been unchanged, then I would expect the new lens to fit a little bit looser on the eye. This normally does not cause a dramatic change in the clarity of the vision. However, different contact lens materials fit on the eyes differently and if your doctor has prescribed a different contact material, it is entirely possible that the new lens made up in an 8.9 base curve fits the same as your old lenses fit with an 8.5 base curve.
I also see that you used to wear the same prescription in both eyes and that now the prescription is different. If you accidentally reversed your contacts (put the left lens in the right eye and the right lens in the left eye), you would have perceived a dramatic change in vision. You could try switching the lenses to see if that clears the vision.
The crustiness of your lids in the morning suggests that your eyes are inflamed. This may be caused by a number of factors that include infection, sensitivity to your contact lens solutions or irritation from the fit of the contact lens to name a few. The only way to determine what is causing your symptoms is to see your optometrist, describe your symptoms and concerns, and have your eyes carefully examined and your contact lenses reassessed. Infections, contact lens fitting issues and sensitivity to solutions can arise at any time, and must be dealt with when they occur.
I hope this is helpful.

Dr. Smit

Rae wrote:
I have monthly wear multifocal contact lenses.  I don’t wear them every day, maybe once or twice a week.  It seems a waste to through them out once a month when I’m not wearing them every day all day long.  I’m wondering if I can replace them every 6 or 7 weeks rather than every 4 to 5 weeks.

ANSWER

Dear Rae

Thak you for your interesting question. It is never a good idea, based on the ocular health, to stretch any replacement scheduled that was prescribed by your eye care practitioner. On the other hand, I can understand that you feel that the lenses are waisted by disposing them after 5-6 uses only. They still are a month old and they have to be discarded.

My recommendation would be to ask your optometrist to fit you with daily disposable lenses which could be more appropriate to meet your needs. These lenses are manufactured for a single use and are cheaper, based on your use, than the monthly disposable. They are also safer considering that each lens, while used, is new and delivers more oxygen to the eye. You do not have to deal with chemicals to store and clean them, which can alleviate allergic/toxic reactions. A pair of lens that is stored in a case is no longer sterilized after 5 to 6 days. If not used, you have to re-sterilize them before to wear them.

Daily disposable lenses are available in multi-focal lenses or in mono-vision with one lens fitted for far and the other one for near.

In summary, you have to comply with the recommended schedule of wear that was prescribed but there is another more convenient solution for you that are daily disposable lenses, the safest mode of contact lens wear in the market.

Thanks for your interest.

Dr. Langis Michaud, OD, MSc, FAAO
Associate Professor
Université de Montréal, School of Optometry

Joanne wrote:
I am 25 years old, I am farsighted with a contact lens prescription of +5.25 in my RE and +5.50 in my LE.  I am just wondering how bad this is.  I am worried that I am going to go blind.  Most of my friends with hyperopia have +2.00 or around there.  I just went to the optometrist and she changed both of my eyes by .50.  I’m worried that it is going to keep getting worse.  She told me that they consider +6.00 bad.  I am not far from that.  How high do contact lens prescriptions go for hyperopia and when do they consider your eyesight to be really bad?
Thank you

ANSWER

Hello Joanne,
Please allow me to reassure you that you will NOT go blind from farsightedness.  Contact lens prescriptions can be custom made for almost any prescription (even up to +20.00), so you don’t have to worry about not being able to wear your lenses.  That being said, the likelihood of your prescription progressing to anywhere near that number is extremely low.  Although your prescription may still change a little bit, it probably won’t be very much.  Your eyes are not “bad”, and even if they progress to a +6.00, they still won’t be “bad”.  Being 25 years old, you’ve got about 75 more years of use on those eyeballs.  Keep having regular eye exams and you’ll be just fine.

Dr. Donati

Andrea wrote:
Hi
I have been doing contact lens trials. I have narrowed down my choice to dailies but am not sure of which brand / size to pick.  My trials range from BC 8.5-8.7 and diameter 14-14.2; the strength is 1.5+.  Before I commit to a year supply, I want to make sure that I am getting the best size and brand combination for my eye (I only need a lens for my right eye).  Shouldn’t I be comparing lens with the same measurements instead of variation in brand, diameter and base curvature? How do I know if the issue is the fit vs. lens brand?  For example, if the Logic 1 day (14, 8.6) feels like a better fit than 1 day Acuvue moist (14.2, 8.5) and Ciba Daily (8.7) should I try the Acuvue and Daily with the same measurements as the Logic before deciding? I find the logic 1 day least noticeable when wearing (14, 8.6). The Ciba Daily (8.7) moves around and has fallen out. The Acuvue moist is comfortable for the first 10 hours.  I won’t be able to see my optometrist for 1 1/2 weeks and only a few trials left.  Hopefully I can get a few more trial lenses before making a decision. Thanks in advance.

ANSWER

Andrea,

Each brand of disposable contact lenses comes in certain parameters.  Basically the lens brand determines the fit as each brand of daily disposable usually only has one base curve and one diameter.  To explain further you cannot try an Acuvue or Ciba daily disposable in the same parameters as the Logic 1 day because they do not exist.  The diameter and base curvature with soft contact lenses, especially daily disposables have little effect on the fit in most cases.  It’s kind of like one size fits all.  An 8.5 vs. 8.6 vs. 8.7 are of negligible difference with this type of lens.  For most people any of these base curves will fit well.  The thing that will determine the comfort is the type of material and the coatings/solution the lenses have been sitting in.  For some people one brand may be more comfortable and for others a different brand may give the best comfort.  As long as your optometrist says that they all fit well on your eye and that your vision is good, it is up to you to decide which one feels the best.  It is quite possible that more than one of them may feel good and give excellent vision.  In that case either one will be a good choice for you.

Dr. Carol Doman

Marie wrote:
I just came down with a case of viral pinkeye. I know I shouldn’t wear my contacts, but I can’t see without them. I don’t have glasses, nor can I afford them. I live alone and need to continue functioning in society - but without my contacts, I can’t. I need to wear my contacts.
How do I take care of my eyes while still managing my life?

ANSWER

Marie,

The only way to get rid of an infection is to leave your lenses off until the eye is completely healed.  The Virus / organism causing the infection can stay in the material of the contact lens and continually re-infect your eye.   You will need to start with a fresh pair of lenses once the infection is done.   I’m sorry, no one should even consider wearing contacts unless they also have a pair of glasses as a backup.

Dr. Joan Hansen, Optometrist for CAO

Christine wrote:
For a few years, I have been wearing Acuvue Oasys contact lenses, -2.50 in both eyes.  Late this past winter I ran out of lenses, and was forced to wear an old (but never before opened pair of Acuvue 2 lenses, which were -2.25.  When I got my eyes examined shortly thereafter, I was told that my prescription was unchanged, and I was given two boxes of my trusty Acuvue Oasys -2.50’s.  I immediately started having “dry”-feeling eyes, trouble focusing, both at my computer screen, and far distances, and I was getting daily headaches (which I never get).  After 6 weeks and three pairs of the Oasys lenses, I decided to try the last pair of unopened Acuvue 2’s (the -2.25’s) — and all of the problems disappeared instantly.  (I also had no headaches or other problems when I wore my eyeglasses).  Today I am trying some new Oasys lenses with a -2.25 Rx, but all of the same symptoms (dryness, headaches, etc.) are returning — in ONE DAY!

I was wondering if perhaps my problems were with the difference in BC measurements of the Acuvue 2’s and the Oasys lenses - the Acuvue 2’s have a BC of 8.7 and the Oasys have a BC of 8.4.  Any ideas?

ANSWER

Hi Christine,

What you are describing is very strange.  It is weird because you were wearing the Acuvue Oasys lenses successfully for a few years.  The base curves would not cause the problems you are describing.  Did you change contact lens solutions at all?  Do you suffer from any allergies?  If everything has stayed exactly the same there is no good explanation as to why you are now having trouble with the Acuvue Oasys lenses.   I would talk to your optometrist about possible changing your contact lens solution to ‘Clear Care’.   This solution cleans the contact lenses extremely well and is excellent for comfort.
Dr. Doman

Teresa wrote:
I have worn contact lenses for 45yrs and never had a problem.  However, with my last 2 prescriptions I do not see as clearly as I can with my glasses that are +5 years old. In fact I see better with my glasses. The new contacts are monovision but I believe that with my previous contacts both lenses had the same prescription. I realize aging causes changes in the eyes but I can’t help but think that the prescription and/or fit are wrong. I am 60 years old and both nearsighted and farsighted. Bifocals don’t work any better than monovision.

ANSWER

Teresa,
I am not surprised in the least that you can see better with your glasses than with your monovision contact lenses.  Monovision contact lenses are designed to have one eye see in the distance and one eye see up close.  As a result only one eye is working at a time.  Although this does work well for a lot of people, with your glasses you would be using both eyes for distance and near vision.  Two eyes working together are always going to work better and therefore see better than one eye.   I find that bifocal contact lenses in some cases will work better than monovision contact lenses because both eyes will work together, but it sounds like you have tried these and they didn’t work well for you.  There are numerous types of bifocal contact lenses on the market, so it might be worth trying a different brand.   Bifocal or multifocal contacts are not perfected, so usually the vision will never be quite as sharp as with glasses.  Do you wear soft or hard contact lenses?  If you wear hard contact lenses sometimes the corneas can become warped over time, which will affect vision.  In this case it is necessary to stop wearing the contact lenses for a period of time to allow the corneas to return to their original shape.  In certain cases people get to a point where neither monovision or bifocal contact lenses will work well and in those cases going to distance only contact lenses and reading glasses over the contacts may work better.
Dr. Doman

Peter wrote:
I have mild myopia in both eyes (-1.00) and “mild” astigmatism in my left eye. I am trialling soft, disposable contact lenses and find that middle-to-near objects are often blurry (with both -1.00 or -0.75 lenses, but with my astigmatism uncorrected as I’m told it is very mild).

My optician says there is nothing he can do as this is due to my myopia being mild combined with having the contact lens “on the eye” (unlike with glasses), and suggests I wear glasses for “near vision” work and contacts for outdoor sports, etc.

Is it really impossible for me to have contact lenses that give me good near AND far vision? I’d quite like to wear them every day for both near and far vision.

Thanks

ANSWER

Dear Peter

This is an interesting question. As a contact lens expert, I am shocked to withness in my everyday practice how eye care professionnals handle astigmatism in contact lenses. In my book, this is a major mistake to not fully compensate for astigmatism, with appropriate toric lenses. In fact these professionals should be convinced of misleading the public and of malpratice. Astigmatism distorts the vision even if the amount of astigmatism is low. To compensate for it, what your optician did (wrongly) is to increase the amount of myopia. This is called fitting with a spherical equivalent technique. THis is not helping your vision at computer distance or at near because an increase in myopic correction triggers an increased accommodation effort that  can end up with ocular fatigue and a blurred vision. This is exactly what you have experienced.

In the past, astigmatism was undercorrected or spherically compensated because of the bad quality of soft toric contact lenses. They were not accurate, not stable in the eye and did not provide better vision compared with spherical lenses. This is not true anymore. Modern design of contact lenses are available and they are really stable, even for small amount of astigmatism. I strongly recommend Oasys Acuvue for Astigmatism, Air Optix Torics or Cooper’s Biofinity Toric as very good products. There is no rational to not use them on a day-to-day basis. At least, every eyecare practitionner should at least propose trying toric contact lenses and let the patient to decide if this is a better option than a spherical lens. I had patients with major myopic correction and small astigmatism who said WOW when i fitted them in toric contact lenses (for the first time) but I had also some patients who were low myopes with higher astigmatism who did not find any difference in their vision comparing spherical and toric contact lenses. Since there is no way to know in advance what the outcome will be, the only rational approach is to try it (toric vs spherical) and to let the patient experience the difference.

If your optician is not familiar with toric contact lens correction, or denies the value of it, consider consulting an optometrist that is skilled in contact lens fitting and ask to try toric lenses. There is no reason to not see clearly at near and intermediate distance with these lenses except if you are 45 years old and over where presbyopia can come in play. Even then, astigmatism should be considered to correct your vision in contact lenses. We can use monovision strategy or to use multifocal toric contact lenses as well.

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