Cataract Surgery and Flickering Vision

I had the surgery yesterday adn went to see the surgeon today. I'm happy
with the result but the only thing that bothers me is ocassional flickering
vision. Flickering usually happens when I read (the operated eye is set for
a reading distance). According to the surgeon, the flickering comes from
reflections off the edge of my IOL and should go away once my IOL is settled
down inside my eye and as my brain learns how to respond to the IOL He also
added that some people see shadows instead of flickering.

So, is the flickering vision something that I should not worry too much?
Granted, it's been only one day since the surgey, but I cannot help
thinking, "How wonderful it would be without the flickering?" :-)

Fidelis K wrote:
> I had the surgery yesterday adn went to see the surgeon today. I'm happy
> with the result but the only thing that bothers me is ocassional flickering
> vision. Flickering usually happens when I read (the operated eye is set for
> a reading distance). According to the surgeon, the flickering comes from
> reflections off the edge of my IOL and should go away once my IOL is settled
> down inside my eye and as my brain learns how to respond to the IOL He also
> added that some people see shadows instead of flickering.
>
> So, is the flickering vision something that I should not worry too much?
> Granted, it's been only one day since the surgey, but I cannot help
> thinking, "How wonderful it would be without the flickering?" :-)


Maybe itll go away. Give it time and see. By the way, you made another
thread here:


http://groups.google.com/group/sci.m...baf7ccafba867c


Check out the replies!

A monofocal was implanted was due to real cataract. The operated eye was
20/100 and the n.o. 20/70 with contacts.

"sdavies6" <(E-Mail Removed)> wrote in message
news:RwMCg.3547$(E-Mail Removed)...
> I'm curious about your surgery. Was it a real cataract, or a Clear Lens
> Extraction? What kind of viison did you have before? How good is the
> vision in the non-operated eye? Is the Mutlipiece a monofocal or a
> multifocal lens?
>
>
> "Fidelis K" <(E-Mail Removed)> wrote in message
> news:4tMCg.25$(E-Mail Removed)...
>>I had the surgery yesterday adn went to see the surgeon today. I'm happy
>>with the result but the only thing that bothers me is ocassional
>>flickering vision. Flickering usually happens when I read (the operated
>>eye is set for a reading distance). According to the surgeon, the
>>flickering comes from reflections off the edge of my IOL and should go
>>away once my IOL is settled down inside my eye and as my brain learns how
>>to respond to the IOL He also added that some people see shadows instead
>>of flickering.
>>
>> So, is the flickering vision something that I should not worry too much?
>> Granted, it's been only one day since the surgey, but I cannot help
>> thinking, "How wonderful it would be without the flickering?" :-)
>>
>
>

Fidelis K wrote:
> Does anyone knows how visual acuity measured with the Snellen Chart
> corresponds to a minus diopter?

> For instance, what is the diopter for 20/70?


> Thanks.



I do. I have been researching this for some time and have seen the
results of many people, almost always myopes. I have even made a
formula that attempts to show how blurry youd see from an objective
point! The math is based on the blur circle on the retina caused by
defocus in diopters.

Someone at 20/70 is likley to be -1.5 diopters myopic. Take spherical
equivalent if astigmastim is in the mix.


-.25 diopters results in minimal blur and doesnt cost a single line.
Sometimes half a line at most. Only malingering people make a deal out
of this.


-.5 diopters results in a reduction of a single snellen line. If 20/20,

then your UCVA would be 20/25. Correction is not needed.


-1 diopters is the smallest amount of blur that people start to
complain about and the lowest prescription that justifies very low
dependance on glasses, such as for driving. Normal people go most of
the time without correction. UCVA generally is 20/40 to 20/50


-2 diopters blurs enough for part time glasses wear. Can easily go
without glasses around the house and for intermediate distance. UCVA is

20/100 to 20/150. Alot of websites say its 20/200 but I disagree. One
problem is many snellen charts have nothing between 20/100 and 20/200
so someone could be just shy of 20/100, yet be put down as 20/200.


-3 diopters starts getting bad. My research shows it to be 20/200 to
20/300, but some websites say its 20/400 but I disagree on it being
this bad.


-.75 diopters will NOT blur to 20/70 in a normal healthy eye. Many
people see 20/30 with such a low minus and dont need correction.


-2.5 diopters will almost always blur more than 20/70 unless you have
20/10 BCVA or you cheat and squint.


Great thread! Im sure the optometrists here can share their experience
on the average snellen score for a given myopic prescription of -.5,
-1. -1.5, -2, etc.

sdavies6 wrote:
> So, if I wear a -12, and that is not corrected to full strength, probaly a
> 12.5 or 13 would be, what is my distance reading. If I'm not mistaken, I
> can be considered legally blind in that eye (thankfully, it is one eye, the
> other is damn near perfect), without a correction.


If you are near -13 in that eye, you would be seeing about or nearly
20/4000 without correction! A -12 correction would cost you 2 lines if
you are -12.75 say instead of 20/30 BCVA at -12.75 youll be 20/50 at
-12.

sdavies6 wrote:
> So, if I wear a -12, and that is not corrected to full strength, probaly a
> 12.5 or 13 would be, what is my distance reading. If I'm not mistaken, I
> can be considered legally blind in that eye (thankfully, it is one eye, the
> other is damn near perfect), without a correction.
>
>


Careful who you get your advice from. Ace is a retard with no training
or experience in anything.

sdavies6 wrote:
> Thank you, I'll take that into consideration. Of course, if you read my
> post, you'll see that I did not ask anyone for advice.



Dont mind Serebel, he is a loney old man who denies two of his lasik
"quirks" and likes to call others "retard"

I am not a doctor and whatever I say is my opinion


"Snellen numbers are pretty worthless at that level. Ace is the only
one who
cares, and his "20/4000" answer is as good as any, because he doesn't
realize how those measurements would vary from one person to another,
one
room to another, one examiner to another."


Make a 20/4000 letter(preferabily an E) measuring 68 inches and youll
get a measure. There is an objective way of measuring defocus blur
using the "blur formula" which ive developed. If you keep the variables
constant, the only difference will be in the ability to interpret blur
which can be made quite constant by training those with poor blur
interpretition.


"I was just wondering; nothing anyone says regarding the definition of
blindness or what my visual acuity is, makes a difference. I am still
left
with a bad eye that is worthless without a contact lens, and then
pretty
good, and a good eye, which is . . . good."


How did one eye get so bad? Were you born like that? How far can you
count fingers in that -12.5 eye? Probably about a foot and a half.

Dr Judy:
> Despite Ace's claims, uncorrected acuity is a very poor way to predict
> refractive error. His estimate of 20/70 uncorrected converting to
> -1.50 would be accurate +/- 1.00 , giving a range of -0.50 to -2.50.
The problem is, if someone said he was 20/70 I would have no idea if he
has a refractive error or a neurological pathalogy resulting in low
vision. The other way around where if this person gives me his
prescription, then I can convert. If someone says he is 20/70, I will
ask for more information. If he says he is myopic then I can estimate
him to be -1.5
If another person says he is -3 and wants to know his UCVA, its 20/200
to 20/300, but usually closer to 20/200.



> At -12.00, any formula for conversion breaks down and unaided acuity,
> if needed, should be measured.
This would be about 20/3000, not that anyone should go without
correction for vision this bad, would be scary! Even at my -4.5 and
20/600 its an inconvinence at best without correction except for
reading, eating, showering, sleeping or if im doing nothing.


> "Legally blind without glasses" is a meaningless term.
We call it functionally blind and this is when you are off the charts
or worse than 20/400 then you cant really function without correction.
Low myopes under -3 can function reasonably well without correction and
very low myopes of -1 usually only wear glasses for driving or watching
movies.


"Fortunately, I am not legally blind. With the lens I am corrected to
around
20/40 or so. My right eye needs no correction."


Sounds like mild amblyopia in the worse eye. What does the blur look
like in comparsion to the right eye? Is it anything like myopic blur or
some strange distortion like everything is smeared or appears dull and
of poor contrast? Someone said amblyopia blur was much like peripheral
vision in his other normal eye. Its not just blur, you cant really
focus on anything.


"I was born with two good eyes. Starting late high school and
progresively
ever since, I'm now 56, one eye becoming myopic and the other stayed
good.
My eye doctor has no idea why and I've heard it is unusal, but not so
unusual as to be a candidate for the textbooks. Without my contact
lens I
couldn't see the numbers of fingers a foot away, at least, not
clearly."


Has any medical reason been ruled out? Sounds like unilateral
pathalogical myopia, a degenerative disease/condition where myopia goes
out of control and only slows or stops in your 30s or 40s, some very
severe cases it never stops and myopia has been reported in the
literature to exceed thirty(30) diopters! pathalogical myopia is
usually bilateral and a serious condition that results in low vision
and blindness if myopia gets too high, the likehood of retinal, macular
and other complications become certain at some point. Your -12 is more
on the mild-moderate side of pathalogical myopia, severe cases can hit
the -20 point! Some pathalogical myopes are born myopic, I know one
that was born -10 and is now -20 with poor corrected vision and sees
pratically only light perception without correction! At -12 you can
barely count your own fingers from a foot away. Would you be able to
count them at all from a foot and a half away?

I was thinking amblyopia because you can only be corrected to 20/40 in
that -12 eye. If it is not ambylopia, then it is some sort of retina or
neurological problem, very common in extremely high myopes.
Optometrists say myopia in the double digits often results in reduced
BCVA, 20/30, 20/40, 20/50 or worse.

If you are -12 in contacts, doesnt this mean youd be -15 in glasses?

As for pathological myopia:


http://www.visionww.org/drswindsor-myopia.htm


http://www.webmd.com/hw/health_guide_atoz/hw122243.asp


High degree myopia (sometimes known as pathological myopia or
degenerative myopia) is a chronic, degenerative condition which can
create problems because of its association with degenerative changes at
the back of the eye.


You can find lots of articles about pathological on google


What is pathological myopia?
Myopia of more than -6D is a degenerative disease and is called
pathological myopia or high myopia.

This is a degenerative disease. Why premature degeneration in such
young subjects? unknown but with a definite hereditary pattern.
Posterior half of the eyeball including the vitreous shows
degenerative changes.
Usually starts in early childhood.
Myopia usually exceeds -6D.


Most people have mild myopia and there are no serious problems.

However, rarely, the eyeball continues to grow and myopia becomes
progressively worse. This is called pathological myopia. People with
this type of myopia are at an increased risk of developing certain
other eye problems, which can sometimes lead to blindness. For example,
a few people with severe myopia may get retinal detachment, which is
when the retinal lining separates from the back wall of the eye. This
requires urgent surgical treatment to prevent permanent loss of vision.



*your eyeball(for one eye) kept growing and your myopia got
progressively worse and became extremely high at -12 contacts(about -15
in glasses) and you can barely count your own fingers from a foot(can
you still count them from 18 inches?)

sdavies6 wrote:
> I don't think I can only be corrected to that vision. For some reason, my
> eye doctor has chosen to not give me a full prescritpion. She explained it
> to me once before, and I've forgotten her reasoning. I assume, if I wore a
> minus 13 lens, I would have 20/20.
>
> I would have to wear a very thick lens, too thick for comfort and an obvious
> mismatch with the other lens, which would be plain glass. I do not think
> that's an option.



Well if you are over 40, he may have given you monovision. Another
reason is that -12 is the highest "available" contact, past that and
youll need an expensive custom made contact(can be soft or RGP) Were
you ever 20/20 in that eye before it became so bad? Did you get an
over-refraction over that -12 contact to see how much undercorrection
is occuring and your BCVA? Wouldnt you be more than -15 in glasses if
you are more than -12 in contacts?