Not sure what to do next

[Lia]

Hi, I had an eye exam yesterday at a major chain of UK opticians and am very concerned about the result. My prescription went up from -1.50 L&R to L:-2.00 -0.25 x 150 and R:-3.50. The optician only said it was a large jump but didn't seem concerned. She marked my prescription 6/6 for the left and 6/7.5 for the right eye. This seems a very large jump to me, it's more than double in one eye.
I took away some trial contact lenses which are -1.75 and -3 and have made an appointment to go back in two weeks to check if they are okay. But after wearing them yesterday I'm certain that the right eye is too strong. It was very uncomfortable.
What should I do - go back and get them to re-do the test or go somewhere else and get a second opinion? How easy is it to get a prescription wrong?
I hope you can give me some guidance, I don't mean to criticise your profession, but I found this a very scary experience. I also feel a bit powerless because I don't really understand how the prescription was decided, Ijust know it feels wrong. Thanks.

[chip anderson]

If you have a complaint and it isn't something you can live with for 2 weeks, call and go back for a follow-up. A competent practioner will check for over correction (by hopefully checking your vision with your contacts on) at two weeks and it's easily detected (especially if you have brought your complaint to the practioner's attention).

Do not be overlly concerned about increases in myopia at your age, especially if you have had a long bone growth spurt.

Chip

[hcjilson]

is that the numbers were not drawn at random based on your previous Rx. They were a result of what you told the practitioner you saw most clearly with. That is not to say that mistakes can't happen, particularly in transcription, but that is a rarity today.

That having been said, you are the only one who can see through your eyes and I'm sure you know how you see. If your vision is unacceptable by all means follow Chips advice and schedule a recheck. I would not let the difference in the numbers of your Rx cause you to think something is wrong. It is quite common for that to happen.

Good luck.

hj

[Lia]

Thanks. Would the difference in the thickness of a diopter or so be very noticeable in rimless with thinner lenses, and would the difference in prescription be noticeable?

[Pete Hanlin]

A one diopter difference would certainly be noticeable when viewing through the lenses, and would likely cause an increase in lens edge thickness as well (depending upon the size of the frame, whether different frames were used, and the material of which each set of lenses was made).

Additionally, there are several possibilities which could explain the rather dramatic change in your Rx. Make your concerns known to your Optometrist or Ophthalmologist when you return for your CL follow-up.

[Darryl Meister]

The first thing that I would have found curious is the fact that, even after the rather significant change in your right eye prescription, they weren't able to correct your visual acuity to 6/6 (or 20/20) vision in the right eye. While 6/7.5 (20/25) is certainly perfectly acceptable, I would certainly suggest asking the refractionist to confirm the prescription, just to be on the safe side.

Best regards,
Darryl

[LaurieC]

.....get a second opinion. But many things can cause a refraction to be wrong. Or, it may be correct but you just need the significant change in steps. The eye transmits the image but the brain does the interpretation. Sometimes the brain doesn't like a drastic change. Many people don't realize they need an RX or that they need their's updated because the change is so gradual htey compensate. But a patient should never hesitate to return to their practitioner.

[chip anderson]

Lia:

A good optician can beef up the thickness of the thinner lens so that they both match at least in this respect.

Chip

[Lia]

Really grateful for the replies, so thanks. A couple more questions if I may without taking advantage ...

1. Is such a difference between two eyes (-1.50) unusual?
2. If the prescription for my right eye is still significantly more than the left does it mean that I will find it very uncomfortable to go without them, will my eyes feel unbalanced or will the left one compensate for it?
3. Will I have to wear them fulltime?
4. Will a difference of a diopter or so be noticeable to other people even if they don't put my glasses on?
5. If my glasses prescription for the right eye is -3.50 why is the contact lens prescription only -3?

I have a contact lens check up booked for 9 January. I called and said I was pretty uncomfortable with the right eye so they're not going to process the order for glasses till then. Meanwhile I'm feeling my right eye is giving me what I can only describe as a pulling sensation when I'm not wearing any correction.

[LaurieC]

First off you're not taking advantage. We are a group of people who love our profession and the vision care we give to others.

1. Is such a difference between two eyes (-1.50) unusual?
No it's really not all that unusual.

2. If the prescription for my right eye is still significantly more than the left does it mean that I will find it very uncomfortable to go without them, will my eyes feel unbalanced or will the left one compensate for it?
Your stronger eye will generally dominate when not wearing correction. Sometimes your brain will actually suspend vision in one eye. This is the concept for monovision contact lens, IE, one eye for reading, one eye for distance. But please see the next answer.

3. Will I have to wear them fulltime?
Well I'm not your refractionist but this RX indicates full time wear in my humble opinion.

4. Will a difference of a diopter or so be noticeable to other people even if they don't put my glasses on?
Not with good quality lenses generated by a good quality lab.

5. If my glasses prescription for the right eye is -3.50 why is the contact lens prescription only -3?
This is something called vertex distance compensation. In other words the distance from the surface of your cornea changes what correction is needed.

:) :) Meanwhile I'm feeling my right eye is giving me what I can only describe as a pulling sensation when I'm not wearing any correction.
This may be caused by eye strain as you struggle to see without correction. It could be tiring the six muscles that insert into the cornea for movement. If one or more tires at a different rate the stronger ones will pull. This is also something experienced while wearing glasses with a wrongly place optical center or with someone who has what's called commonly "lazy eye".
A little more advise from me is that we are all trying to help but we don't know your full vision need history, any other health conditions such as high blood pressure, unusual blood sugar levels, etc so the hands on professionals available to you may well come up with something we don't. I want to reassure you that we understand what you're experiencing is likely very disconcerting to you. However we see it much more often than the lay person might imagine. Try not to worry, everything you're describing is quite resolvable.

[Optom]

Hello Lia,

I appreciate opinions of Darryl Meister & LaurieC and I second their opinion.

Regards,
Optom

[chip anderson]

I appreciate Laurie C's opinions but the difference in power required for vetex @ -3.50 is nill. It is certianly not 1/2 diopter.
There is something else involved here, compensation for flat base, some theory that patient will not adapt or something.

Vertex compensation @ -4.00 is only .12 diopter, less for lesser powers.

Chip

[paw]

Your difference between the 2 eyes is not a big deal. My sister has -4.00 in one eye and -1.00 in the other. Not a big deal there, either.

[Lia]

Chip - my previous lenses were -.25 less than my glasses. The prescription for my left is -1.75 contacts/-2 glasses. Wonder why the right is so much less, like -3 contacts/-3.50 glasses?

Is adapting to this change potentially an issue, is that why sh'es gone for a lesser strength?

If the final prescription is somewhere close to the original -3.50, any tips for acclimatising? Thanks :)

[chip anderson]

Lia:

CL RX will be less than spectacle (on minus lenses) if:
1) Rx is over 4 diopters and practioner is allowing for vertex (distance from spectacle to eye). Stronger the Rx the more strength is reduced.
2) Patient is pushing 40 years of age and practioner wants to cut down on distance to give less effort required for accomodation (eye muscles flexing lens for near distance).
3) Some practioners just have some strange theories, especially if they are very young and think they know more than they do.
4) On rigid lenses and some stiff soft lenses the power must be adjusted to the shape of the tear layer (which is of itself a funcioning lens) between the eye and lens.

Chip

Also note: On plus precriptions the above is applied in reverse, Contact power will be increased. Or more plus added for near.

[mrba]

I'm surprised all of these experts aren't just a bit concerned. I'm getting into this thread a little late and may have missed something on the read through, but I would advise two things.

First of all your rx change in not unheard of and the difference in powers is not rare. The sensations your are expiriencing in your eyeballs are due to the newness you are adapting two, as well as a touch more prism you may be sensing when you look off center in your lenses (toward the periphry). it sounds like you may be a bit over minused, a common mistake in refraction. The person who checked you initially should re-check this

However, all this aside, Did your refractionist mention anything about blood sugar or diabetis? Where I am from, a one diopter change is almost a mandatory trip to your internist for a blood test. Did the person doing the refraction ask you if you had to go to the bathroom a lot, or are you overweight (common symptoms)?

When you go back bring this up and see what they say. Better safe than sorry.

mrba

[mrba]

Ok I cant resist with all these opti-nerds around.

quick story,

I had a patient come into a store I was working at. She had gotten her glasses in the UK 5 years ago. Power was roughly
-12 OU. Anyways long story short, her PD was off in the old glasses by about 10mm and they were polycrap. No prism was found in the new refraction.


Patient didn't even notice when her new ones were made the right way.

"Everyone is sensitive"

yeah right

:hammer:

[Lia]

hello mrba - I'm not overweight, don't go to the bathroom alot and and am generally fit and healthy so I wouldn't imagine I have diabetes. The optician didn't seem concerned about the size of the increase, but she was in a hurry, next person was waiting. Thanks for raising it, I'll check it out.

[mrba]

"I hope you can give me some guidance, I don't mean to criticise your profession, but I found this a very scary experience. I also feel a bit powerless because I don't really understand how the prescription was decided, Ijust know it feels wrong. Thanks."

Case and point, you shouldn't need to go to the internet for your answers (although you are to be applauded for not giving up).

Our profession needs much criticism. Most people that I have worked with are really not competent to be doing what they are doing in optical. My state has extreamly low standars for opticians. A close relative of mine is a professor of Optometry and when he proctored the state boards last year, he told me the candidates couldn't perform the basics in alarming numbers.
Glad to hear your in good health. I tend to bring up the more obscure points.

Final Considerations;

Your age. If you are under thirty a change that big would be less reason for alarm. Over forty and it would definately be the exception.

If you are having trouble adapting to the new Rx it wouldn't be unheard of to have your practitioner cut it back a bit. You don't need to take it all at once. Remeber that the eye is a biological organism that not only responds to the laws of Physics, but it also attached to your brain. Psychology is a prerequisite for optometry school for a reason. It sometimes takes a patient a month to adapt to a big change. Even though their acuity may be clearer their brain just doesn't like it.

cheers

[LaurieC]

mrba said:
I'm surprised all of these experts aren't just a bit concerned. I'm getting into this thread a little late and may have missed something on the read through, but I would advise two things.

First of all your rx change in not unheard of and the difference in powers is not rare. The sensations your are expiriencing in your eyeballs are due to the newness you are adapting two, as well as a touch more prism you may be sensing when you look off center in your lenses (toward the periphry). it sounds like you may be a bit over minused, a common mistake in refraction. The person who checked you initially should re-check this

However, all this aside, Did your refractionist mention anything about blood sugar or diabetis? Where I am from, a one diopter change is almost a mandatory trip to your internist for a blood test. Did the person doing the refraction ask you if you had to go to the bathroom a lot, or are you overweight (common symptoms)?

When you go back bring this up and see what they say. Better safe than sorry.

mrba

Please reread as several excellent points you made were reiterating ones already stated. And yes that included blood sugar but not in an alarmist way.

Laurie, may be from the same state as you but am licensed in three other tougher ones, have my ABOM and care very much about the quality of my profession, as it appears you do, C

[Diane]

Out of one of my courses...

Anisometropia

Unequal Measure
The condition when the two eyes require a different degree of correction (1.00 or more) but the same kind of correcting lens (+ or -)
The condition may cause vertical prism imbalance at near or cause a difference in the retinal image sizes between the two eyes

Anisometropia
Unequal refractive errors
Minimum Difference for Classification is 1 diopter
Becomes a Visual Problem at Approximately 2 diopters

That said, sometimes more sensitive people...have more difficulty adjusting to this change. If the Rx has been different throughout eyewear (visual) history, the increase is less of a concern. This much change at one time can cause an adjustment. The brain sometimes doesn't like us to change too much, too fast.

I agree with a lot of the other posts, including the one from mrba that we are probably opti-nerds. I agree with Chip that vertex compensation for a -3.50 is usually not necessary, and don't quite understand a 1/2 diopter compensation for contact lenses. Have you discussed with your doctor if you have some type of accommodative or convergence problem??? I disagree that it shouldn't be checked out more thoroughly. Based on your corrected visual acuities, it doesn't appear that you are being fit monocularly, but that may be something to ask as well. Sometimes with contact lenses, a prescriber will drop the minus power for someone for better near correction. (???!!!) With spectacles, the patient will sometimes simply remove the spectacles to see up close, and hold the reading material very close.

Even obviously healthy young people (and I'm not sure that we know your age) have health problems. Diabetes, high blood pressure and thyroid conditions can affect anyone, and can have an impact on vision.

OK, we're all adding something, as we are opti-nerds, and want to get out 2 cents worth in, and these are a few of my thoughts, although not all of them.

Diane

Happy New Year to you all....
:cheers:

[Lia]

Happy New Year to you all and I'm sorry to drag this out, but someone always asks a new question!

I didn't give my age but I'm 41. I could see very well with the -1.75 contact lens at near range, but less well (although not impossible) with the -3.00 but I did get a strange straining sensation in my right eye when wearing them.

I'm not surprised that my prescription increased, I was expecting that, but not quite so much. It's been constant for a few years but I've noticed a difference in the last year. I imagined that you'd have to be nearly blind to need a -3.50 in a glasses prescription and I don't think I am yet, although with no correction (and I don't have the new prescription in anything other than contacts) that straining sensation is often there.

Thanks to you all, you do a great job on this site - it must be a real pain when punters like me find it!

[Diane]

Lia said:
Happy New Year to you all and I'm sorry to drag this out, but someone always asks a new question!

I didn't give my age but I'm 41. I could see very well with the -1.75 contact lens at near range, but less well (although not impossible) with the -3.00 but I did get a strange straining sensation in my right eye when wearing them.

I'm not surprised that my prescription increased, I was expecting that, but not quite so much. It's been constant for a few years but I've noticed a difference in the last year. I imagined that you'd have to be nearly blind to need a -3.50 in a glasses prescription and I don't think I am yet, although with no correction (and I don't have the new prescription in anything other than contacts) that straining sensation is often there.

Thanks to you all, you do a great job on this site - it must be a real pain when punters like me find it!

Lia,

At 41, you may be becoming presbyopic....which means that (sorry dear) the crystalline lens along with the rest of the accommodation system is changing with age. I'd be curious how long ago your previous exam was and even prior to that. What is your exam history, and changes each time. You mentioned that you could see up close just fine with the -1.75, but a strain on your right eye with the -3.50. I'm guessing that means up close. How is your distant correction with the -1.75? Do you know which is your dominant eye? Did your doctor, prescribe a monovision correction in your contact lenses? That means that you are "supposed" to see out of one eye for distant correction and the opposite eye for near correction. I question that only because of your statement about vision. Your spectacle prescription would indicate that you have NOT been prescribed with this modality...but one never knows. Stranger things have happened. Are you attempting to see how well you are seeing out of each eye independently, or attempting to focus with both eyes at the same time? Meaning, covering one eye at a time???

I'm thinking out of the box a little, with not enough information, but it's what we do here, sometimes.

I'd love to have a complete history....I could ask tons of questions.

Anyway, another question for you.

Diane

[Lia]

Hi Diane, thanks for your reply. Here’s my unremarkable history: first prescription age 30 was –0.75, then a few –0.25 increases to –1.50 two years ago.

Yes, I checked what I can see through each eye as well as together. I can see fine for distance and close up with the –1.75. With the –3.00 I can see well for distance but not as close for near work although I could certainly read without difficulty. The straining sensation I had was constant, I wasn’t doing a lot of close work that day. My dominant eye is my right I believe. The optician didn’t mention mono vision, although she wanted me to ‘try’ the –3.00 contacts. I asked if it was wise to process the glasses prescription of –2 and –3.50 and was told she was happy with that but just wanted me to try the –3 contacts. What was she thinking – that they'd be too strong, too weak? Why 0.50 less than the glasses prescription for the right and only –0.25 less for the left?

I’ve had the straining sensation since the exam when not wearing correction – is that eyestrain or something to do with the difference between the two? If it is why would it still happen wearing the contacts? And if my dominant eye is my right would that explain it? Am I a difficult customer??? Would it be appropriate to ask the optician to try reducing the prescription in the right or would that offend??

[Lia]

Diane - would reall value your opinion on the history and symptoms that I posted.

My 9 January check up was cancelled due to the optician being ill -I've rescheduled for Tuesday. So, if you have the time and the inclination, I'd be glad to hear from you :)