Bad vision at the end of the day, and w/ light changes:

I'm having problems with my vision at the end of the day.

I'm a computer programmer, and spend a fair amount of time in front of the
computer when I'm not at work. I suspect that has something to do with my
problem. My vision is fairly clear most of the day, but from twilight on I
get distinctly more nearsighted, even indoors. Sometimes I will experience
blurry vision early in the day if I change my environment, for example I had
very blurred vision after walking into the library the other day.

If I squint, it helps bring things into focus, sometimes dramatically.

I've been to two eye doctors. One basically said "I don't know what's
wrong, try stronger glasses". The other suggested it was the near work I do
all day, causing my eyes to lock into near focus. He suggested some eye
exercises (which I have been doing) and also gave me a new prescription. I
had what seemed like an extensive run of tests with each doctor, and neither
of them found anything they considered alarming, but I'm still not soothed.

I am 33 years old. From what I have read, an increase in nearsightedness is
unusual for people my age. This worries me. Also, the fact that my vision
problems are much worse at night, and plausibly related to changes in the
light level, seems significant to me, but not to either of the eye doctors.

My main concern is that something is going on that will make my vision
continue to get worse, that would have been avoidable if I had known what to
do.

Has anyone here had similar experiences, or have any insight to offer beyond
what I've already been told?

Matt

 

(Matt C.) wrote in message

Dear Matt,

I hope you are not wearing minus lens glasses now.

The first thing a person sees on the threshold of
nearsighedness is some loss of distant vision in
semi-darkness.

This is a good indication that you should review
the major opinions about the eye's behavior, and
reach a point where you make a decision about
your course of action.

The opinions are strong -- and directly opposed.

Others are going to post statements to the effect
that working all day at 15 inches (-2.5 diopters)
has NO EFFECT OF THE REFRACTIVE STATUS OF THE EYE.

The alternative I suggest is to use a plus lens
for working on the CRT, and of couse check
your vision by reading an eye chart. If you
are interested, then read my site.

http://www.myopiafree.com

I give this advice to pilots who have the
maturity to understand the nature of this advice.
So read the "legal" part of my site to understand
that the responsibility is yours.

So enjoy the "read", and think about it.
Take no action until you judge that you
are comfortable with you choice.

Best,

Otis
Engineer


*****

 

(Matt C.) wrote in

Do you have any risk factors for diabetes?

Scott

 

A couple of observations: If squinting helps, then the problem must be
optical in nature. You could have a form of myopia that is transient and
related to your long hours at the computer. This is not uncommon, and is
caused by your accommodative muscle not being able to relax.

What would cause your vision to change with light level? For one thing,
the pupil changes size. Besides regulating the amount of light, the pupil
also helps to eliminate spherical aberration. Do you see better or worse
in a low light environment?

Something that can cause blurred vision, but should not be responsive to
squinting, is dry eyes caused by staring at the monitor. A person with
marginally dry eye will also experience changes with the environment, air
currents, humidity, etc., but not with illumination levels.

DrG

(Matt C.) wrote in

 

(Otis Brown) wrote in

I am not. I had already decided not to wear my new prescription at the
computer. My vision had only gotten worse with my previous prescription.
At present I do not wear any glasses while doing computer work. I will
probably try the positive lens suggestion from your website.

In some ways this is comforting, to think that my case is somewhat normal.
However, the light sensitivity is pretty pronounced in my case, and I'm
still somewhat worried that more is going on here.

From what I have read so far, your arguments seem plausible, and your
recommendation for treatment does not sound very risky. I will probably
give it a try. If I do, I'll report back here in a few weeks.

Thank you for the response and for the information on your website.

Matt

 

Not that I am aware of, nor any other indicators of diabetes. However, I'm
planning to go get a pee test just to cross this off the list for certain.

Thanks for the reply.

Matt

 

Ok. I have noticed that my vision degrades even on days where I have not
been working at the computer. I've not measured this closely, though.

Noticeably worse with less light. Again, I have not measured closely, but
it seems like my vision gets slightly worse as the day goes on, and then
significantly worse once the sun starts to go down.

It seems like fluorescent lighting also causes my vision to get blurry.

My computer monitor was pretty bright--too bright--for quite a while. Is it
possible that this has something to do with my light sensitivity, perhaps my
eyes got used to an unusually small pupil size?

Thanks for responding.

Matt

 

(Matt C.) wrote in

Could you give us your spectacle prescription, please?

DrG

 

Sure. It says, R: -50 sph, L: -175 sph. I assume this means -.5 and -1.75
in the diopters that I've been reading about.

I am not sure this was the most reliable eye exam. I was wearing my old
glasses (considerably weaker than this prescription) and actually tested
better when I took them off than when I was wearing them. For what that's
worth.

Matt

 

(Matt C.) wrote in

OH, now that's interesting. Without your correction, you are functioning
monocularly, i.e. right eye for distance and left eye for near. Even with
spectacles, that is a fair amount of anisometropia (prescription
difference) between the two eyes, and you may not have good binocular
vision under those circumstances, either. It is possible that your blurred
vision is a result of poor binocularity, unstable fusion, or excessive
accommodation secondary to fusion problems.

By the way, when do you wear your eyeglasses? Are your symptoms occurring
only when you wear your spectacles?

Try covering one eye and see what happens (with spectacles on, of course).
As you can see, there are several possible scenarios, all involving stress
on the visual system.

Also, I do NOT advise that you wear low plus reading spectacles. Save the
$15 for a thorough binocular vision work-up and possible contact lens
fitting.

DrG

 

I have tried covering first one eye and then the other. It does not seem to
change anything (other than the obvious decline in vision when I have my
right eye closed). If there is something more sophisticated I can try, I
would certainly be willing to do so.

I'm not wearing them at all; the prescription hasn't even been filled. My
vision is usually quite clear during the day. (Like I said before, I
question this most recent prescription.) My symptoms typically show up at
twilight and at night. I do sometimes have blurry vision during the day
when I change location. I'm forming the hypothesis that these daytime
problems are related to changes in the light level or possibly fluorescent
lighting.

It seemed to me, and still seems to me, that the eye exercises he
recommended (looking at distant objects periodically), and the prescription
he gave me, are in direct contradiction to each other. I decided to just do
the eye exercises and skip the glasses.

(Also, my vision got worse when I was wearing my old prescription regularly.
That played into my decision to not get the new glasses.)

I am now contemplating getting this stronger prescription filled, just to
make sure that the problems I'm having with night vision are in fact
correctible with glasses. Kind of an expensive experiment, but I'd would
like to confirm that my night vision problems are lens-correctible.

As above, it doesn't seem to make a difference. I could try wearing an
eyepatch during the day, if a brief test is not sufficient.

Do you mind discussing why? The argument for wearing plus lenses for close
work makes sense to me.

Matt

 

(Matt C.) wrote in message

Leukoma> > Also, I do NOT advise that you wear low plus reading
spectacles. Save the $15 for a thorough binocular vision work-up and
possible contact
lens fitting.

Matt> Do you mind discussing why? The argument for wearing plus
lenses for close work makes sense to me.

I would like to hear the reasons also.

Best,

Otis

 

The fact is that Matt C. reads with his left eye, which already has a power
of +1.75. He might be using his right eye to view the computer screen,
depending on the working distance. But, Matt is essentially monocular,
with a natural form of monovision. I know that it is far easier for Matt
to understand the simplistic notion of wearing plus lenses for close work
than it is for him to understand the concepts of binocular vision.

Otis, on the other hand, knows better...or does he?

DrG

(Otis Brown) wrote in

 

(Matt C.) wrote in

As I said in another thread, your left eye (-1.75) has a focal distance of
about 25 inches. Therefore, within that range your left eye does all the
work. This is called monovision. At night, under conditions of poor
illumination where peripheral visual cues are lacking, diplopia tends to
occur, or a situation in which the blurry image from the left eye is
superimposed on the clearer image from the right eye typically ensues.
Prebyopes who wear one contact lens for close work often complain of night
vision problems, especially as the presbyopia and the power of the reading
lens increases.

Lack of fusion and accommodation can lead to other issues, such as
convergence problems. Also, there will be an intermediate range of vision
where both eyes will try to dominate. Typically, this condition tends to
become more embedded as the "near-dominant" eye becomes more nearsighted
until the symptoms of a binocular vision disorder become more pronounced.
Speaking as one who has seen and treated countless cases like yours,
treating yourself with over-the-counter reading glasses makes absolutely no
sense to me. I dare say that I would be surprised if it made sense to any
eye care professional.

Having said that, I recommend that you put the $15 toward a thorough
examination from a good optometrist who will take the additional time to
analyze your work situation and try different lens combinations, as well as
giving you a thorough explanation.

DrG

 

(Matt C.) wrote in message

Re> Has anyone here had similar experiences, or have any insight to
offer beyond what I've already been told? Matt

Dear Matt,

Subject: The second (engineering) opinion

You have recognized that a plus lens might be
a good idea for consistent close work.

Indeed this is the recommendation of optometrists
who are familiar with your type of work.

It is true that the plus lens is a lower cost
item -- but that is not the point.

The point is that maybe you had a "bad day" when
your eyes were measured at -1.75. Perhaps
the OD has a "bad day". Maybe your eyes
are more like the old prescription.

You might double check this yourself.

In any event here is the experience of
a pilot who wat measured to be -1.0 diopters.

Maybe his experience with be a factor in your
decision.

Just remember, an ounce of prevention is
worth a pound of cure.


Best,

Otis
Engineer


______________________________________________


1. Name and Date: Matt, Pilot 3/16/03

Subject: Otis, can you help me from -1.0 D?

Hi my name is Matt B. I am 21 years old and have a
prescription of:

Left : -0.75 and
Right : -1.00.

I am very interested in improving my vision to 20/20.

This prescription is not good enough for the Royal Air Force,
at present I would fail the eyesight test.

My dream is to become an RAF pilot, so any efforts that I can
make to improve my vision without surgery would be ideal.


2. From: Otis

Subject: Recovery from -1.0D, or 20/70

Dear M. B., I appreciate your interest. Generally, -1.0
Diopters is considered to be equivalent to about 20/70.

No one can guarantee success, but a number of pilots have
cleared their distant vision by the plus-lens preventive method.

I will provide all the assistance I can. However, you must
make all the confirming measurements. Best, Otis


3. Name: Matt B.

Subject: How should I use the plus

I have read all the items on your site and to be truthful am
somewhat confused.

Does this mean that I can prevent my eyes from getting any
worse or can I improve them.

Should I wear them all day or just for close up work as I am
doing now?


4. Name: Otis

Subject: Initial Info: How to use the plus

Dear MB, The plus lens is sold in the USA everywhere with no
prescription required. Values run from +1.0 to +3.75 D

Select a lens of about +2.0 diopters. Pick up some reading
material an push print, i.e., find the point of blur for
comfortable reading.

Practice reading, for 10 minutes, and then look over the tops
of the lens at the eye-chart. Some times you will see rapid
clearing by this method. Best, Otis

5. Your Name: Matt

Subject: More Measurements

I found that I could easily read the letters. I downloaded a
Snellen chart which I printed out and stuck on my wall.

At twenty feet I found that I could read the 20/20 line
although it was not crystal clear when using both eyes.

With just my left I could see 20/30 although I could make out
most of the 20/20 line and with just my right eye I could see
20/40 easily but most of the 20/30 line.

6. Your Name: Otis

Subject: Vision Status

To: MB, Pilot. I am pleased you checked your vision an
found it to be approximately 20/40 under room illumination. You
now have a base-line to compare your improvement.

You need to improve by about +1/2 diopter. Please read pilot
Christer's comments on his efforts. They should help you
understand what it will take to clear your distant vision.

I hope you understand that this is a slow process. If you
keep working, you can achieve what Dr. Colgate achieved. Best,
Otis

7. Your Name: Pilot M.B.

Subject: JAA Test, Part 1

Otis, Today has been a good day!! I passed my medical
without a hitch - you should see the huge grin in my face. I know
it is only a JAA class 2, ... but I was quite worried that I
would fail the vision part. The examiner made me cover one eye
and look through a mirror at the chart on the wall behind me.

The chart was the one with the rotating Cs which I found
pretty easy. After that I had the standard Snellen chart, at
normal room illumination, which I also passed.

8. Your Name M.B.

Subject: Pass JAA -- Part 2

I'm not sure quite how I did it but I scored a 6/6! Looks
like all the work that I have been doing is paying dividends.

I want to personally thank you Otis for introducing me to
this method of clearing up my distance vision. I am now more
motivated than ever to keep up with my efforts.

Think I might have a beer or two this evening, such a weight
has been taken off my shoulders. I raise my glass to you my
friend.


9. Your Name and Date: Otis 3/29/03

Subject: JAA Test, Part 3

Matt, Both of us are VERY PLEASED at your success. 6/6 means
you read at a distance of 6 meters what the normal pilot can read
at 6 meters.

The size of the characters is 0.88 cm. They should write:
6/6/0.88cm to be perfectly clear to the pilot who wishes do his
own checking.

As you know, pushing print, doing your own eye-chart
checking, and using the plus lens properly is the key to success.
Congratulations! You must continue this work (even though
you are at 20/20) to make certain your vision stays at
20/20. Best, Otis

 

I appreciate the explanation. Two things make me wonder if my night vision
problems are substantially due to diplopia.

1) Closing my left eye at night does not improve my vision in my right eye
(which I agree is doing all the distance work). Is there any lingering
effect with diplopia? If so, could I test for diplopia by keeping my left
eye closed for (say) 20 minutes?

2) If, at night, I make a slit with my fingers and peek through it, my
vision is dimmer but much sharper (it takes some meddling to get it right,
but it works). This agrees with what my most recent eye doctor said about
my problems with my night vision (larger pupil size). It does not sound
consistent with my problem basically being an inability to integrate images.

I agree that OTC reading glasses are not going to help with any problems
that are basically caused by monovision. However, I am still concerned that
the near work I do all day is degrading my distance vision generally.

What would you think of the idea of me getting a pair of prescription
"reading" glasses such that both of my eyes were near their outer focal
limit while I was at work? Say (just a guess), R: +0.5, L: -0.25?

If you think this is not a good idea, do you think it is likely to cause
actual harm, or just that it is pointless?

I am hoping to find an eye doctor that I can see eye to eye with, so to
speak.

Matt

 

(Otis Brown) wrote in

What do you think of Dr. Leukoma's observation that my vision is basically
monocular? I find the argument for the plus lens for close work plausible,
but it is true that if I get reading glasses that work for one eye, they
will be completely out of range for the other. Do you consider this
significant, and if so do you have any advice about handling it?

Been doing this with a home-printed Snellen chart. I am finding a lot of
variation, depending on time of day, illumination level, and type of
illumination.

I appreciate your interest and your suggestions.

Matt

 

I do not agree with Dr. Leukoma.

But check it out. Can you see three D objects? Has anyone
of the oDs you consulted stated you have mono-vision?
There is a slight difference between the two eyes.
Differences of up to 0.75 diopters are with in a
normal or gaussian spread. This was suggested
by Dr. David Robins in a previous post -- and I agree with it.


Matt> I find the argument for the plus lens for close work plausible,

Good, but from past experience, I can tell you it is not
easy and takes a great deal of personal resolve.
If you are casual about it -- just do not bother.
The pilots who have used the method go ALL OUT.
You can check my site:

http://www.myopiafree.com

for information to that effect. If you decide to
take any action at all -- think about it. It is like
advocating that a person go on a diet and lose 20 pounds.

While conceptually correct -- most people are simply
not going to do it.

The minus lens is indeed 100 times easier. Most doctors
do not recommend that a person use the plus -- simply
for the reason that the person concerned just will not
do it.

That depends on the physics of the situation. Since you
have been examined by an OD, you can feel confortable
that he has ellimanated all ORGANIC problems with your eye -- and
has determined that a -1.75 dipoter lens will sharpen
your vision to the maximum extent possible. It is
possible that it is "over-prescribed", and I would check
this by reading 3/4 inch characters at 20 feet in room
illumination. Most people will not even do this simple
check. Please do not do any of this on my account.
You asked for general information about "potential alternatives"
and it is always pleasant to think about them.

Since we will never know what actions you might take, the
issue is a matter of your own judgment.

Matt> Do you consider this
significant, and if so do you have any advice about handling it?

If your vision were 20/40 and 20/50 (by your own checking) I would
not consider the issue as important. Typically you will see
this difference between the eyes that have 20/20 and focal
states of +1/4 and +3/4 diopters. In this case both
eyes would be 20/20, and the person would not be
aware that there was a difference of 1/2 diopter.

You should ask youself how important your distant vision
is to you -- really? Unless it is VERY IMPORTANT, such
as you do not "make" the RAF, I doubt that you would
have the motivation it really takes to clear you distant vison.
[This is NOT a criticism, it is just the way most of us
are.]

You will get a lot of hostility against this concept that
evolution designed a very sophisticated eye that "follows"
the visual enviroment, but that is the way that I see it.

These arguments have nothing to do with money. Rather
they have goal of learning and understanding new concepts -- and
methods that can develop from them.

Best,

Otis


******

 

AND A PERCENTAGE OF ODS AND MDS RECOGNIZE THIS ALSO.

Here is some commentary by Dr. Robert Levy who reflects
the "second opinion", about keeping the minus lens
off your face, except for driving a car when it is
absolulty necessary.



IS IT TRUE THAT THE EYE DOES CHANGE ITS FOCAL STATE
WHEN PLACED IN A CONFINED ENVIRONMENT?


The Health Profession's Response to "Problems With Poor Vision".
[The previous "myth" was that there is no relationship between
the focal state of the eye and its visual enviroment.]

Dr. Robert Levy:

I must strongly disagree with at least one "myth" about poor vision
Dr. Jay Siwek mentions [Consultation, 9/11/91]. He says doing close
work does not harm your eyes and then goes on to talk about three
sight- threatening diseases. While it is true that close work does not
cause the kinds of blindness that glaucoma, cataracts and macular
degeneration do, such fine focusing for extended periods can cause
nearsightedness, a far more common occurrence.

Day after day, year after year, I see patients who get more and more
nearsighted from doing close work, particularly if they have been
wearing a distance prescription while doing their close work. The
vicious cycle is that you read and do your homework, become
nearsighted, get distance [negative lens] glasses and when you go back
to read and do your homework you become more nearsighted.

People who take their glasses off to read (if they can) or who wear
bifocals [plus lenses] to reduce the prescription for near focusing
show a much slower progression into nearsightedness than those who
read with distance glasses on. One study of an Eskimo village being
taught to read showed that after two generations of reading, virtually
none of the grandparents' generation needed distance glasses, about
half of the parents' generation did and virtually all of the
children's generation did. This is the best example of reading and
close work causing nearsightedness.


_______________________

 

(Otis Brown) wrote in

As I understand it, the way to use positive lenses for vision rehabilitation
is just to read print at your outer focal limit. I don't understand why you
say this takes a great deal of personal resolve. I've tried reading this
way; it's mildly inconvenient, but I'm pretty sure I could get used to it.
Is there something I'm missing?

Matt