Vision fluctuation & eye strain

[patrick]

Hi all,

I visited my optometrist a few weeks ago and she found out something new about my eye discomfort. I'm just curious if someone here has something similar like me.

My optometrist already suspected for a while that the culprit of my dry eyes and mgd is eye strain.

She now found out that my prescription varies during the day. It is not very much,but still it is present and rather undesired of course.

My prescription goes from -1.0 in the morning to +0.75 in the Evening.
My optometrist says that this could cause my eyes to have to focus all day long and obviously that is quite straining to the eyes. It also makes you blink a lot less than you should and if this goes on long enough it is unavoidable that mgd comes into the play.

All this could very well be caused by the refractive surgery i had in 2005.
The pressure in the eyes varies during the day and if for whatever reason the cornea is thin enough the shape will differ constantly. It has become unstable and therefore the prescription as well.

I already heard so many stories about what can cause dry eye and discomfort,but this explanation is all new to me. To be honest it sounds a little odd to me. But then again i'm not an expert in this field at all.

Anyone here who heard of this? Does it make any sense?

Any input is welcome of course!

Patrick...

[Rebecca Petris]

Patrick,

Yup, makes sense to me (I think). I think perhaps your optometrist isn't saying that the eye strain is causing dry eye per se but rather your symptoms (or a big part of them).

From personal experience honestly I can't draw any clear line between pain from eye strain and from dry eye. Also, the fluctuating vision that some of us get from refractive surgery can cause a LOT of eyestrain. I don't get any of this fluctuation or eyestrain when wearing RGPs or sclerals, but without them it's just as bad now as it was ten years ago.

[Scout]

Yes, this has happened to me.

I had LASIK surgery in 1999, so it was a long time ago but I had this same problem with periodic changes in my prescription. It did cause strain, eye pain and occasionally migraine-like headaches.

You are very lucky that your optometrist has diagnosed the problem. This happened to several people I knew but at the time, no doctor would acknowledge that this could be a side effect of refractive surgery.

In the beginning, my doctors would encourage me to try to go without glasses or contacts. But even if the correction is very small, the strain of trying to see without the correction caused pain. So I started wearing glasses again and that really helped.

What I found out was that the cause and effect is very complicated and at times, confusing.

In my case, the refractive surgery and the post-surgical infection in my left eye that occurred caused my eyes to become extra sensitive and reactive to allergens and substances in my environment. The resultant inflammation and swelling caused my corneas and eyes (and sinuses) to swell enough to cause pain in my eyes and head and to change the correction--resulting in a change in prescription.

The resulting change in prescription caused more pain and headaches because I then had the wrong glasses prescription and a focusing problem. For a few years, I had about 4 different glasses that I used depending on the prescription for that day.

Years later, I figured out that I needed to find out what substances in my environment I was sensitive or reactive to and remove them from my daily life. I tried allergy eye drops for a few years and that helped in the beginning, but eventually they made things worse due to the preservatives and chemicals in my eye from the eye drops.

I have been fairly successful discovering any chemicals or substances or allergens I am sensitive to and removing them from my environment. I have worn the same glasses prescription for over 4 years now.

For me, the inflammation caused the swelling and the swelling caused the prescription change. Finding the source of the reactions that trigger the swelling and removing them from my environment has really helped.

Scout

[Hopeful2]

WOW! I wonder if this might be happening to me?

I had my refractive surgery 10 months ago. I still have a prescription in both eyes, with one around +1 and the other around -1. I also find that my vision varies depending on the lighting. I think it might have something to do with a small ablation zone.

I wonder if all the changes in lighting over course of the day could account for eye strain and inflammation.

Scout, when you say your eye swells, do you mean the eyeball itself? Is it a perceptable difference in size? I have often thought that my eyes seem larger at the end of the day.

Thanks for the advice.

[patrick]

Hi again,

Thanks for your input!

Rebecca: i recognize what you mean with not being able to draw a line between dry eye pain and pain caused by eye strain.
It is very difficult to tell the difference. However from my own experience i think that dry eye pain although this is of course very annoying isn't causing the headaches i think i experience from eye strain/vision problems.
I mean that dry eye pain is more limited to the eye and surrounding tissues and eye strain and vision problems are probably causing more problems like headache and muscle pain. But again,these theories i assume,i'm not sure of anything.
About the sclerals,do you suggest these could be a solution for me? One of the properties of sclerals is that they stabilize the cornea and therefore it is not unlikely that they can eliminate the fluctuation in vision for the greater part,or am i wrong here?
My dry eye is still in the moderate regions. Tbut has never been under 5 seconds and i'm not overly aqueous deficient.It is not surprising sclerals have never been discussed as an option,because my particular case just isn't considered severe enough to take that step yet.

Thanks again for your advise. It is highly appreciated!

Scout:

If i understand you clearly your fluctuation in vision is caused by swelling of the sinuses and eyes due to allergens?
Does your prescription changes during the day,like me? Or is it more that your prescription changes periodically?
So it's stable for a certain period and than changes back or forward to stay that way for another period?
If you had 4! Different glasses,with different prescriptions of course how did you decide which glasses to wear that day? Was it a case of trial and error?
I tend to react to many allergens to. This has always been the case with me,but before my refractive surgery it never ever caused any problems with my eyes.
I now use allergo comod drops 4 times per day. Is doesn't contain any preservatives. Can't say it has reduced symptoms considerably,but it doesn't add any additional problems as well so i just keep on using them. Maybe it prevents my eyes to react to certain allergens and maybe not. Nobody knows for certain Including myself.

Thanks for your advise!

Hopeful2:

I think with 10months it is not unusual to still have a bit of fluctuation in vision.
I guess there is still some healing going on and your vision will probably stabilize itself in the next few months.
Maybe make an appointment for a check up at the clinic where you had your surgery and ask them about these issues you have.
Whenever they propose to do a touch up procedure on you i'd say be very very careful with that!
Many people here have had a bad experience with such procedures.

Thanks for your reply!


Btw. I'm aware that my english is somewhat poor here and there. Sorry for that....

Patrick...

[Sammy B.]

Patrick as you know I am post-LASIK by a few years now and I do use readers (not just over-the-counter drugstore readers, but readers designed for my eyes) at the computer. I was experiencing headaches and deep soreness-type feelings behind my eyes. I was afraid it was dry eye. Well it was eye strain.

Get some glasses that will help you during your computing/reading hours and the strain will lessen.

Rose

[patrick]

hi rose,

how are you?
from what i've read you're doing a lot better lately. isn't it?
i will for sure get me a pair of readers asap.
just to give them a try and see what happens. hopefully the strain lessens a bit. sure would be nice!
may i ask what prescription readers you have? my prescription is only +0.75 and to be honest that seems so little to me that i can't imagine this would make a hughe difference. but on the other hand it could be possible. you don't know untill you try i guess.

patrick...

[Hopeful2]

Patrick, do you know if you have any astigmatism? My prescription is only about +1 but with a -1 astigmatism, it is actually worse. I have also noticed that I see colours differently out of each eye. My right eye seems to let in more light and the daylight actually seems brighter out of that eye than the left eye. Maybe you have some of this happening too?

[Rebecca Petris]

About the sclerals,do you suggest these could be a solution for me? One of the properties of sclerals is that they stabilize the cornea and therefore it is not unlikely that they can eliminate the fluctuation in vision for the greater part,or am i wrong here?

Any kind of RGP is good for fluctuating vision, and for those of us with dry eye sclerals are sometimes the only kind of RGP we can tolerate long term. I don't think it's so much about stabilizing the cornea as making the instability irrelevant. The combination of the liquid layer and the hard material makes a sort of artificially smooth/stable refractive medium that compensates for irregularity and/or instability in the cornea. That's how I think about it anyway.

[Sammy B.]

Patrick,

Yes I am doing much better. I am now experiencing an overflow of tears which I am not sure how this was brought on, perhaps a bout with blepharitis (I had stopped doing my warm compresses 2x daily) or allergies? At any ate there is no pain anymore and for that I am grateful.

Hopeful2 has a great suggestion about having an astigmatism. I do have that and perhaps you do too?

Here is my post about my glasses:

http://www.dryeyezone.com/talk/showt...ght=#post50584

Rose

[Scout]

Scout, when you say your eye swells, do you mean the eyeball itself? Is it a perceptable difference in size? I have often thought that my eyes seem larger at the end of the day.

No, I don’t actually see swelling, I just feel increased pressure and pain.

If i understand you clearly your fluctuation in vision is caused by swelling of the sinuses and eyes due to allergens?
Does your prescription changes during the day,like me? Or is it more that your prescription changes periodically?

It was a long time ago, but for a time after LASIK, I had both types of changes. I experienced the periodic changes due to increased inflammation and the changes at the end of the day from (I think) mostly eye strain and night vision problems.

So it's stable for a certain period and than changes back or forward to stay that way for another period?

Yes, it did happen that way. At first I thought it was what happened to everyone after LASIK, but then I realized that it doesn’t happen to everyone. I think it happens much more often that doctors would like us to believe, but not everyone is as sensitive to the changes in vision. Some people can tolerate the fluctuations easily and other people get eye strain and headaches.

If you had 4! Different glasses,with different prescriptions of course how did you decide which glasses to wear that day? Was it a case of trial and error?

Yes, pretty much trial and error. I often carried one extra pair with me and had the other 2 at home. So I usually only changed from one to another.

Btw. I'm aware that my english is somewhat poor here and there. Sorry for that....

Your English is quite good, actually. You are very easy to understand. But I might suggest that you email Rebecca and ask her to change the title of this thread. There is a lot of useful information that you and other members are sharing here that will be difficult for other people to find if there is no title to define the subject.

Maybe you can entitled it something like, “fluctuation in vision” or “eye strain and vision changes.”

Scout

[Rebecca Petris]

Great idea Scout, I just renamed it.

[patrick]

Thanks!
For some reason i couldn't change the title of this thread when i wanted to change it with the edit button.

I'm very busy at the monent,so not very much time to reply now.
I will of course as soon as i have a little more time on my hands than right now....

Patrick..

[hirentherock]

Thanks to the title change, i felt to read the thread as i find similar problem with me.

I had cataract surgery on 6th march 2012.Im 30 yr old male with dry eye and sjs, rough eyelids,low vision.

When i went for surgery. the doctors were hardl able to do the keratometry coz eyes would get dry just so soon.
They were able to do the keratometry several times though with many attempts.But interestingly,
they found cornea size different with every attempt.They were saying sometimes it comes to 47 sometimes 53...I asked them to see my other eye if it gives same kind of variation.But they found other eyes cornea size to be of same measurement on 3 attempts.

Also, they checked my needed power on the machine.But in morning it showed -10 and in evening when my eyes were feeling more dry and fed up due to all the check up procedures it came to -17!
So variation of power upto 7 Diopters!!

This is making me confused.Even it was confusing for doctors a bit, as i saw by the way they were discussing my pre surgery procedures.i heard the doctor suspecting KERATOCONUS. Corneal irregularities are associated with keratoconus.

But when i checked about this to my regular optho doctor (who did not operate me but sent me to a cataract specialist) , he told me due to sjs and dry eyes, cornea gets uneven at times.So mild keratoconus is persistent with such eyes.

Im not sure why this happens. Rebecca or any other BSL wearers can let me know if they face such problems and get benifited with BSLs?Im really curious to know this coz im banking upon BSL to get me out of this problem of varying vision. My other eye is aphakik and has finger counting vision.So i need the best vision in my recently operated eye.

[spmcc]

I thought it was 'normal' for vision to fluctuate in people with dry eyes. I found this abstract on it: http://www.ncbi.nlm.nih.gov/pubmed/20458235. They say that ocular surface physiology changes also.

[Rebecca Petris]

There is more than one type of surface irregularity and vision fluctuation being discussed here so I think it might be useful at this point to back up and talk about the parts of the eye for a moment... if not just ignore my mini-lecture

The front of the eye has three layers that provide the eye's refractive function, that is, clear layers that work to bend light so that it hits the back of the eye (retina) just so. That means three places things can go wrong that affect the stability of your vision:

1) The preocular tear film

In any kind of dry eye disease, obviously the preocular tear film is not fully performing its job and since tear production and distribution are affected, it's totally to be expected that vision will fluctuate as spmcc said. This affects some more than others. I know people whose ONLY dry eye symptom is poor, fluctuating vision. I know people who have bone-dry eyes and who amazingly enough still see 20/20. - Takehome point is that tears are not just there for comfort and to protect the eye - they are the first refractive surface of the eye and essential to clear, stable vision.

2) The cornea (which has 5 layers)

After lasik or other refractive surgeries there are a number of things that can go wrong here that will cause fluctuating vision. It could be small surface irregularities that make it impossible to maintain a smooth tear layer across the cornea (though over time these tend to improve). It could be a small 'effective optical zone' i.e. the diameter of the area that was FULLY treated by the laser (and I don't mean what they programmed into the machine but what actually came out after all healing which can be quite different... this is something verified with a high res corneal topography) - if this is smaller than the pupil gets when it expands, then we can be particularly prone to a widely fluctuating RX in different lighting circumstances.

Some of us have irregular corneas, where the dioptric power varies greatly across the surface of the cornea. There are certain patterns to this (esp. in the earlier days of LASIK things like central islands or decentrations) but often they're all lumped together under a somewhat poorly named category of 'irregular astigmatism'. What it really means is the thickness of the cornea is uneven - in other words, a multifocal cornea. (Suppose you had a pair of glasses with different strengths at different parts of the lens - it's like that but built in.) Long story short, for those of us who have ANY of the other reasons for fluctuating vision - dry eye, small effective optical zone, etc - these irregularities will make the the fluctuations seem even worse.

Then of course there's extremes, like keratoconus (or corneal ectasia as it's known if caused by refractive surgery). Hirentherock that's really different from corneal irregularity in the common sense of the term because keratoconus/ectasia is progressive while irregularity (depending on the cause) can be static.

One of the things that makes this so confusing is that ALL of the cornea-based fluctuation problems get very difficult to diagnose accurately when your eyes are severely dry. The scanning technologies depend to a significant extent on the presence of a decent tear layer. I haven't really kept up with those technologies in the past 5-ish years so there may be better ways to compensate now but that's what I recall historically as often being a problem.

3) The lens (that's the part that flexes to change focus from far to near)

---

Rebecca or any other BSL wearers can let me know if they face such problems and get benifited with BSLs?Im really curious to know this coz im banking upon BSL to get me out of this problem of varying vision. My other eye is aphakik and has finger counting vision.So i need the best vision in my recently operated eye.

Hirentherock, yes, BSLs (really any RGP theoretically, but realistically only sclerals can usually be worn by people with dryness as severe as SJS causes) can stabilize this, because the liquid + hard lens provides an artificially smooth, stable surface to compensate for whatever's going on on/in the cornea.

[hirentherock]

[B]



One of the things that makes this so confusing is that ALL of the cornea-based fluctuation problems get very difficult to diagnose accurately when your eyes are severely dry. The scanning technologies depend to a significant extent on the presence of a decent tear layer. I haven't really kept up with those technologies in the past 5-ish years so there may be better ways to compensate now but that's what I recall historically as often being a problem.

WELL YES DURING my durgery doctor had to try a hell lot many times on topography machine to get my cornea details...they tried putting tear sunstitute many times...but the machine would give error again and again, due to dryness of eye as they told. My schimer test was 12 a week befire the surgery.
Im wondering if i have 12(which is decent compared to 0s), what would happen to those who have totally 0 tear figure??

Thanks rebecca for clearing my doubts on keratoconus.I was frightened to get victim of another eye decease.I was more doubtful for keratoconus coz its smtthing which occurs in teenage, and it is a sign of weak cornea...i already have weak cornea curtseydryness and sjs.

I will be going for BSL after a few weeks...hoping to get better vision.

[Storm]

I do often think that eye strain plays a part in causing MGD and dry eyes even though this is not recognized by doctors. Its like eye glands (both oil and tear) shut down due to eye strain.

I often got very sore eyes before I got new glasses which would fix the soreness. The last time this happened before I got MGD, I had severe dry eyes for 4 months. At that time I didn't make the connection between the dry eyes and needing new glasses. I was really surprised when getting new glasses immediately resolved the dry eyes, in one day.

I never went to an optometrist because my vision wasn't good or was blurry. It was always because my eyes hurt like hell.

I use a different pair of glasses for driving and watching TV than the pair of progressives I use for every day use. I have a cross over problem that is opposite for distance and close and you cannot technically put both corrections in progressive glasses. My eyes will often improve when I use the driving glasses (watching TV). I do have astigmatism which is constantly changing.

[patrick]

Okay, i really didn' t expect this thread to generate so many reactions. Wow!

About astigmatism, i guess that is not the case with me,because my eyes have been examined so many times by now and by different opthalmologists and none of them ever mentioned astigmatism. So i guess that is just not the case with me.
I also did the quick test on the internet the other day to see if any astigmatism is going on,but again. No. Could see everything perfectly clear.

My eyes have also been examined both numbed with drops. The examinator wanted to make sure he got the right outcome. He could see my eyes are accomodating constantly and he said this could make the test unreliable. Numbed the outcome was; od +0,75 and os +1,0. This test was done halfway in the morning. After all with my current knowledge i should have proposed to do this test again somewhere in the evening,because the outcome certainly would have been quite different from the one in the morning.

About the irregularities of the cornea. I don't know. What i do know is that one opthalmologist once said; the person who did the lasek refractive surgery on you did a perfect job. All looks good and the scare has healed very well. He told me this while examining my eyes through a slitlamp. I have to admit i never had any trouble with starbursts or halo's. I'm not sure but i guess those are the first symptoms to occur when you have serious irregularities on the cornea.
However If i look very closely into a magnifying mirror i can very clearly see the edges of the area treated with laser. It kind of looks like i'm still wearing contacts. Which is unfortunately not the case,because than i could just take them out of my eyes to never ever put them there again and give my eyes the break they need so much.

No,the explanation my optometrist gave me for the fluctuation in vision is that probably the shape of my eyes changes slightly during the day due to both a thin cornea and changing pressure in the eye. That the pressure in the eye is changing during the day seems to be normal,but that it causes vision problems obviously is not normal at all.

I know that refractive errors can also be caused by a poor aqueous tear layer. Like rebecca says the tear layer is the very first refractive surface so any defects there can already cause vision problems.
However I don't think that my vision problems exactly fit that profile,because i think my aqueous tear layer is not all that bad.
I just found a report of an eye examen conducted in 2010. This was done in the morning.
Schirmer's ; od 21mm and os 14mm. Osmolarity;293.
Tbut 10 secs. In both eyes.
Recently my tbuts weren't all that good when measured in the evening; between 3 and 6 secs.
At that moment my eyes hurt like hell,i was tired and had to drive for a hour and a half in extremely densed traffic to get to the appointment.

Again,thanks for all your input!
I'm learning so much from it.
It is appreciated highly.

Patrick...

[hirentherock]

Hi,
If i speak about my experience with morning and evening, its reverse compared to what that report concluded...i get better vision, wetter eyes, less pain in evenings compared to morning!Mornings are really hard to pass at times.

Even Dr.Dipinder of pitburg says , those who has less vision morning and gets beter as day pass by , are certainly having a compromised cornea. http://video.osnsupersite.com/video/...3A%20exclusive check this She emphasizes , if "better evening vision" is present with a patients, they need special attention before undergoing any surgery, irrespective of other corneal stats being normal.So such corneas are vulnerable.

I recently had cataract surgery.But since a got new IOL i observed that as soon as i put any eye drops(genteal/antibiotic/pentolate) i get very nice vision up to few seconds...for a minute or two...then it goes to where it was...On this observation rebeccas idea of tear layer deficiency caused vision loss seems to be the case...I cannot conclude this untill i get 3 months completed for my cataract surgery.If tear layer deficiency is causing vision loss then im pretty hopeful for BSLs to be effective to regain significant vision.I would try BSL after 2 months.

[spmcc]

i observed that as soon as i put any eye drops(genteal/antibiotic/pentolate) i get very nice vision up to few seconds...for a minute or two...then it goes to where it was...On this observation rebeccas idea of tear layer deficiency caused vision loss seems to be the case...

If you read Dr. Latkany's book The Dry Eye Remedy, he uses this as a test to reveal dry eye. He writes that "what has happened is that the moisture of the drops has normalized your tear film, and that has improved your visual acuity. But the improvement is temporary, lasting only for a few seconds up to perhaps a minute or so" (pp. 33-34).

[sunshinelover]

Found this thread really interesting . I have had highly fluctuating vision since my refractive surgery 25 years ago . I have asked numerous doctors about this but noone has ever had an explanation . I have noticed worse vision since after flights also that can persist for many weeks . Thought it could be due to air pressure being different in the plane , but now that I have had dry eyes I keep thinking may be due it could was dryness , although I did not feel any dryness . Before dryness hit in Feb I never had any pain or head ache related to my refractive vision either . And I was walking around with highly refractive errors and astigmatism that was walking changing constantly .