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Asking for less than perfect IOL in Cataract Surgery
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Ian Hodgson Opticians Ltd
medicine forum beginner


Joined: 06 May 2005
Posts: 24

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Colour blindness Reply with quote

<g.gatti@agora.it> wrote in message
news:1107345585.778743.71480@o13g2000cwo.googlegroups.com...
Quote:
All problems of colour perception are due to mental strain.

The above comment is a load of ??*!


Colour vision defects, a term much prefered to colour blindness, are well
understood. In the retina
there are three types of cone receptors which respond respectively to red
light, green light and blue light.
The work identifying the visual pigments was done in the 1930's by Arnold
Soresby ( I think). Colour vision problems
are related to the lack of these pigments.

Colour vision is classified as Protanopia (red), deutranopia (green),
tritanopia (blue); there are two
other classifications tetratanopia ( which has a disputed existance) and
true monochromatism ( no colour perception), the
latter being very rare see the book by Sachs (?) about the Trioband
islanders for a fuller explanation.

The underlying cause for the lack of visual pigment is either genetic (
typically 10% of all males have a color vision defect),
or acquired due to disease or drug toxicity. Examples of the former may be
diabetes and the latter alcohol or quinine.

The problems of colour vision following on from a cataract operation may be
due to the spectral transmission characteristics of the
implant, also as you get older the media of the eye change their spectral
transmission. If one eye has an implant and the other does not
I have had reported to me differences in the colour response between the two
eyes.

As to whether one eye only can be colour deficient it is assumed to be
bilateral in genetic cases, though I would not be surprised that uniocular
may occur as, if I remember correctly Dalton who first described protanopia
only had it in one eye. And in acquired cases monocular deficiency
could certainly be present.

The only mental strain will be gatti getting his head around such concepts!

Regards



Ian Hodgson - Isle of Man
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Guest






PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Very Odd Vision Disturbance Reply with quote

Start to practice the methods of the normal eye, discovered by Bates in
the Twenties.

You will see great suprise.

Discard what the doctors tell you, it is all useless crap.

For more information on the true cure of imperfect sight, see website
http://TheCentralFixation.com
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PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Colour blindness Reply with quote

All problems of colour perception are due to mental strain.
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Robert
medicine forum Guru


Joined: 28 Apr 2005
Posts: 1700

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: On the sidelines of eyecare Reply with quote

On Thu, 03 Feb 2005 11:50:04 -0800, dabel@sonic.net (Dan Abel) wrote:

Quote:
In article <v6m401d1j24698b42o03qd9s0q7s99u4k7@4ax.com>, Robert Martellaro
robopt@nospam.com> wrote:


The vision and perspective looking away from the center of the lens will
be very
poor with a bi-convex design. I wouldn't recommend this, but if you want
to see
for yourself make sure that the dispenser will remake them into a more
appropriate lens design if you are unable to wear them.


I'm having trouble seeing what the problem is here. I thought that
*everybody* who had cataract surgery before some time needed these kind of
glasses, and that there would be lots of experience and knowledge about
how to make them. What am I missing?

< snipped>

Dan,

This Rx is much stronger than aphakic glasses, which are typically in
the +12.00 to +14.00 range.

Robert
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RM
medicine forum Guru


Joined: 25 Mar 2005
Posts: 326

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: -20 D under self-treatment, update report Reply with quote

Quote:
Sinc RM can not face scientific truth concerning
the natural eye as a dynamic system --

Where have I ever denied the eye is a dynamic system. Why do you keep trying
to misrepresent everyone as saying this? You are the only one who ever
talks about this. You must think this is some kind of eloquent concept--
it's actually quite elementary. Right down your alley Otis! Even you can
understand it it's so simple. Too bad you don't understand anything about
the anatomy and physiology of the eye-- by your own admission.

Otis misquotes, and lies!


Quote:
Insisting that the natural eye does not
behave as a sophisticated system
is not they way to do scientific research.

Who ever insisted that? Another Otis misquote and lie!

Quote:

So for RM has presented no scientific evidence to
PROVE that a minus lens has NO EFFECT on
the refractive state of the natural eye.

What? I am supposed to provide scientific evidence that a minus lens has no
effect on the refractive state of the eye? Says who? Otis' twisted logic
is incredible!

Otis proposes concepts that are not proven and have frankly been disproven
in numerous studies-- so he turns around and points a finger at eye doctors
using a therapy that is the standard of practice and tells us the WE need to
prove it's efficacy.

No Otis-- you need to prove that what you propose actually helps someone!
Others have tried to prove it and it doesn't work, except for accommodative
myopes which are the isolated cases you like to beat your drum about.

Your logic is twisted indeed!

Quote:
I know that other ODs now support your right
to an "informed choice" about prevention
at the threshold. Why does RM express
fear -- about an honest choice you
could make in this manner?

Where have I ever expressed fear? What a foolish old man you are!

Go away troll!
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Loren Amelang
medicine forum beginner


Joined: 07 Jun 2005
Posts: 11

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Very Odd Vision Disturbance Reply with quote

On Wed, 02 Feb 2005 15:11:38 -0800, dabel@sonic.net (Dan Abel) wrote:

Quote:
Your brain figures out how far away something is by its size. If it looks
tiny, it must be far away.

Well, perhaps "normal" brains might do this. Mine certainly doesn't.

Quote:
This same thing used to happen to me when I was a kid. It was always at
night when I was in bed with the light off and my glasses off. I would be
looking at something, like the doorframe, and all of a sudden it would get
about a third the size, which made me think that it moved away. Since I
was in bed, I didn't really care and never told anyone. I was very myopic
and wore thick glasses every waking moment. I didn't know at the time,
but those glasses make everything much smaller. Since I couldn't see a
thing without glasses, I couldn't really tell that things got smaller when
I put the glasses on. They just got sharper so I could see them. My
theory is that my brain got confused when it was so dark, and it would
snap into "glasses" mode, making everything much smaller. I haven't
experienced this in decades.

I'd say when the object appeared to get smaller, it was becasue your
brain switched _out_ of "glasses mode". With your lenses on, it had to
mentally magnify your retinal images to make them fit the space you
felt around you. Take the lenses off, and this compensation was no
longer needed. But we were taught the world didn't just change size
(except in fairy tales) so it was only in unusual circumstances that
you became conscious of the change happening.

One of my responses to wearing negative lenses through most of my
childhood was to learn to disconnect the perceived size of an object
from its distance. I stopped directly experiencing the change in
perceived size as I moved toward and away from things. I learned to
rely only on perspective and relative motion to judge distance. The
experience of moving toward an object was like "dollying" a camera
toward it while "zooming" the lens wider - leaving the object the same
visual size. (Or in another way of thinking, part of me left my body
and stayed back away from the object while the other part approached
it.)

Of course I knew objects should appear larger as they got closer, and
if you had asked me I would have said they did, but I didn't
experience it directly. After many years without lenses, I'm finally
beginning to learn to re-connect the link between size and distance.
When I remember to mentally switch it on (sort-of like learning to
move a long forgotten muscle) the difference in how the world appears
to work is shocking.

I remember disconnecting the link when I was maybe nine years old, as
a way of adapting to lenses that were otherwise far too painful to
wear. I keep intending to find time to study how the optometric
profession thinks adaptation is supposed to work. Apparently most
people can tolerate the size changes their lenses impose, with only an
occasional artifact like Dan describes.

But as I mentioned, if you had asked me earlier, I would have said I
saw objects get bigger as I got nearer. I wonder how many other
lens-adapted people see such size changes mentally but not in the
direct, vivid, visual way I'm re-learning to see them...

Loren
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Guest






PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Very Odd Vision Disturbance Reply with quote

Quote:
But as I mentioned, if you had asked me earlier, I would have said I
saw objects get bigger as I got nearer. I wonder how many other
lens-adapted people see such size changes mentally but not in the
direct, vivid, visual way I'm re-learning to see them...


I thought the lady was intelligent, but since she uses such terms as
"re-learning to see" I understand she is not.
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George
medicine forum Guru Wannabe


Joined: 02 May 2005
Posts: 102

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Cataract surgery recovery--glare Reply with quote

"David Robins, MD" wrote:

Quote:
If you dwell on the difference, and keep comparing one eye to the opther by
covering 1 eye and checking, no you will never get used to it. Under normal
circumstnaces, most (but not all) people can adapt to the eye-to-eye
difference if it is not too much. However, if the blurry vision is is one's
dominant eye, brain does not like to get used to paying more attention to
the other (nondominant) eye.

The slight yellowish tint is the easiest symptom to get used to, in most
cases.

However, some people, engineers in particular, are so constantly observant
that nothing lets them get used to anything.



My OD feels the same way. He says engineers, scientists, and professors are
the worst patients because they are constantly looking at fine detail,
comparing things, and so on, with their eyes. Damn! I'm all three <grin>...
But knowing I would not give up asking him about it, he admitted that there was
a slight crease in my IOL that might be causing glare. Fortunately it seemed to
diminish over time. Now I have another problem...a worsening case of vitreous
detachment that is clouding my vision... much like a floater. Sure wish there
was a remedy for that!!

George
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otisbrown@pa.net
medicine forum Guru


Joined: 24 Mar 2005
Posts: 1447

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: -20 D under self-treatment, update report Reply with quote

Retin...

You are calling a person that is -20 diopters myopic -- as
having "accommodation myopia".

Even the ODs on this site would not stretch the truth
that far!

They have defined "accommodation myopia" as a person
on the threshold who is "squinting" on the 20/50 line,
and after a period of wearing a plus for all close work -- clears
to pass the DMV-Snellen line.

Perhaps YOU are dumber than dirt, and don't have clue?

Did you ever think about that?

Best,

Otis
Engineer
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PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: -20 D under self-treatment, update report Reply with quote

This RM is truly a very very hard-rock true idiot.
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Andrew Chew
medicine forum beginner


Joined: 24 Mar 2005
Posts: 49

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Very Odd Vision Disturbance Reply with quote

"Jim M" <jckstrw@gmail.com> wrote in message
news:1107321164.139800.89470@l41g2000cwc.googlegroups.com...
Quote:
Hi

I'm having a problem with, I think, my vision and I was hoping someone
could help. It's difficult to explain, but here's what the issue is:

Sometimes when I'm looking at something within a certain distance (I
would guess about 5 feet away at a minimum and a maximum of about 10-15
feet), I see things oddly. It seems like I'm viewing something from a
farther distance than I actually am. For example, I will be sitting at
my desk looking at the wall (a couple of feet away). All of a sudden,
it feels like I'm looking at the wall from a distance of about 10 feet
away. If I blink or look away, it goes away. And this only happens to
things that are sortof close to me. It won't happen if I'm looking
down the street, or if I'm looking at my hand.

Like I said, this is very odd. I had this when I was a little kid--it
used to accompany high fevers, but now it's back (after about a 25 year
hiatus). I've been to my regular doctor and I've been to an eye doctor
to have my eyes examined. I explained the problem to both doctors and
neither has ever heard of anything like this. When I was younger I
underwent a battery of tests (the only one I can remember is the CAT
scan) and they could find nothing wrong with me. Has anyone ever heard
of anything like this? I just went to get a CAT scan yesterday and the
nurse was asking about my symptoms. She suggested a depth perception
problem. Could this be it?

If you would like more information, please let me know. Any help would
be greatly appreciated.

Thank you.

Jim


Do you sufffer from any refractive errors?

I used to get this a lot when I was in my teens - very weird sensation I
agree. I attribute it to the eye or brain trying to adapt to a change in
lifestyle, ie if you suddenly have to do a lot of close work compared to
previously...
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Guest






PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Broken Metal Frames Reply with quote

Thanks for the replies! I was in the mall, and there was this "jewelry
repair" shop. So
I walked in and said "do you repair broken metal frames". They said
"about
10-15 a week!". So they repaired them and included a 1 year guarentee.
Now I
have a nice spare pair to go with my new glasses (once I get them
organized). :-)

-A
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Steven
medicine forum beginner


Joined: 18 Mar 2005
Posts: 3

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: On the sidelines of eyecare Reply with quote

Robert Martellaro wrote:
Quote:
On 1 Feb 2005 11:25:57 -0800, "Steven" <hyperope@yahoo.com> wrote:

Many thanks for the replies. Unfortunately due to other medical
problems I am not a surgical candidate. However, I have found
someone
helpful enough to make a bi-convex lens in this Rx. I am hopeful
this
will help matters, as my vision is so limited right now that just
walking around my house is a problem.

Steven


Dr. Leukoma wrote:
Have you been evaluated for an anterior chamber lens or a ciliary
sulcus implant?

DrG

Steven,

The vision and perspective looking away from the center of the lens
will be very
poor with a bi-convex design. I wouldn't recommend this, but if you
want to see
for yourself make sure that the dispenser will remake them into a
more
appropriate lens design if you are unable to wear them.

Good luck

Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
robopt@execpc.com
~~~~~~~~~~~~~~~~~~
"If a million people believe a foolish thing, it is still a foolish
thing."
- Anatole France


Hi Robert--Thanks again for the help and replies.

I did finally get my new Rx in a bi-concave, ground from a 16-base with
a +2 back curve, and placed in a larger frame. The perspective is a
little different than my previous lenses, which were made from a +20
base, but the significant increase in peripheral vision is more than
worth it. I can't say exactly how many degrees I've gained, though it
seems my overall visual field is at least 50% bigger--hard to quantify,
though.

For the first time I can actually walk down the supermarket aisles w/o
stopping every few feet to get oriented to my surroundings, or just
walk down a city sidewalk reasonably secure in my ability to avoid
people. This is a significant improvement over 20-base lentics, which
gave me just barely usable vision. In addition, it only took a few days
to get used to the different perspective of the new base curve, and
now when I put on my old pair of glasses, everything looks odd, and I
am *very* keenly aware of how limited my vision is with the smaller
lens, and feel very insecure with them on.

Now, my only problem is finding a source for this special-order design.
I had to jump through a few hoops to get this pair, including ordering
an obsolete blank which hasn't been produced in a while. I would hate
to have to go back to the old design. Signet makes a +15 full field
base, which would work with a +3 inside curve--not much more than I
have now. So hopefully I will have a supply in the future, and someone
willing to make them.

Steven
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krishnaraj
medicine forum beginner


Joined: 24 Mar 2005
Posts: 1

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Sty Problems Reply with quote

thanx for your kind response to my query.
I contacted few eye doctors,nobody have given right treatment,they just
prescribed some antibiotic tablets,it seems to be cured for some
dayz,but later after few months it again starts.from past 1.5 year it
didnt appeared ,as i m continously wearing glass,if i go out.
i think thats the only method ,by which i can prevent this sty.

thanx n regd.

krishnaraj.
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The Real Bev
medicine forum Guru


Joined: 30 Apr 2005
Posts: 356

PostPosted: Thu Mar 24, 2005 8:13 pm    Post subject: Re: Asking for less than perfect IOL in Cataract Surgery Reply with quote

drfrank21@hotmail.com wrote:

Quote:
Unless the surgeon is planning on implanting an astigmatic IOL,
it will be a moot point with all the astigmatism you have.
You wont need to worry about 20/20 uncorrected vision @ any distance
because the astigmatic component that you have will prevent that.
Thus even if the surgeon neutralized all or part of your myopic error
the astigmatism remaining will still require you to wear an spectacle
correction.

How good are astigmatic IOLs now?

--
Cheers,
Bev
0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0
Judges are our only protection against a legal system that can
afford lots more prosecution than we can afford defense.
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