Simon,
Give the below my best suggestion, at long range, would be try and get
your thyroid problems stabilised before anything else and then get a
re-exam.General Health problems could be the cause.

Regards


Ian Hodgson - Isle of Man
- quote -

Ian Hodgson opticians wrote:
- quote -

A severe problem? So I gather Im overcoming the issues so that I don't
notice it, but would benefit from prism lenses then?



- quote -

That might explain then why there is still a period of "visual" stress
after work for a couple of hours, and then none in the morning, I guess.

I've just returned to work after the weekend, and after having had my
medication for hypothyroidism increased to 150mcg. I don't notice the
same issues anymore while looking at paper, though it is blurry, I can
fix this with my existing glasses.

I am concerned therefore whether this fixation disparity is linked in
any way to my underactive thyroid, where I learned from my GP that
actually my TSH has jumped from 2.6 to at least over range (ie 5.5) just
in the past month.... Now Im on 150 mcg of thyroxine, things seem to be
getting better. I am curious therefore if there is a possible link, and
therefore whether I should be getting prism glasses.

Though maybe if I got them and just wore them when I felt eye strain
that would be the best option?


- quote -

I have always had problems with fluorescent lighting. I find the light
highly uncomfortable to work in and has always caused me eye problems.


- quote -

I don't recall anything like that sadly. Maybe I need to request it.

Thanks for the advice.

Simon

Simon,

"Simon Dean" <sjdean[at]simtext.plus.com> wrote in message
news:3utqomF12nll4U2[at]individual.net...
- quote -

usually large.

Fixation Disparity measures what is called a heterophoria, this is a hidden
squint, or as I have
stated earlier ocular muscle imbalance.Often the eyes are trying to overcome
the diplopia by working
extra hard. The idea behind the tests is to find out if this is happening.
And give rise to convergence/divergence
insufficiency. Correction of the problem is by either some form of eye
exercises or spectacles using prisms.
(Whilst Mike is correct in that the measurement is done in minutes of arc
corrective lenses are done in prism dioptres.)
The correction is usually split between the two eyes to give a better
cosmetic result, but if the prism correction is low or not easily
equalibly splittable then then highest prism value is placed in front of the
eye exhibiting the fixation disparity.

Regards


Ian Hodgson - Isle of Man

Simon,

'Lots Snipped' and trying to follow several further posts


1) Mallet distance test uses red bars and OXO


2) Ideally it should be the two bars which are out of alignment with just a
single X.
By your description the two eyes are dissociating with the disruption caused
by the polarised visor.
This indicates that you are having severe difficulty in fusing the two
images,one from each eye, into one.


- quote -

have distance problems
and others have near problems, some have both, and sometimes the amount
varies between distance and near.

- quote -

doing is stressing the visual system.
At the weekend or in the evening the may not be the same amount of visual
stress.

- quote -

It is possible the fluorescent light may be exacerbating the problems, due
to the fact that the lights
flicker at 50Hz. Whilst not consciously visible it can be unconsciously
visible.

- quote -

They should at the very least distance and near Mallett (or similar) should
be part of the routine exam.

Regards

Ian Hodgson - Isle of Man

CatmanX wrote:
- quote -

Good. As I expect my vision to change over the course of a year, Im not
going to use my glasses 24/7 maybe a few hours at work or as needed
(it's only the past couple of weeks in six months, that I've actually
needed to use them), so Im not too willing right now to spend a large
sum of money on fancy frames... especially if my vision changes, I just
go and get my eyes rechecked, and get a new pair made up. There was also
a reason for me buying a cheap pair in the first place, in that my
vision was like +.75 in one eye, +.5 in the other, with a slight
astigmatism. It was debatable whether I'd actually get any benefit...
but I have. From this £39 pair.


- quote -

Ahh. You must work in the south of england. There are a lot of people in
the rest of the UK who might not be able to afford the latest designer
glasses, so knowing I can get a pair of glasses that work, and
relatively cheaply, is always going to be a factor for me. I can trust
the optician to give me their honest opinion and not try to sell me a
pair of glasses without giving me the results as I walk out the door...
Price, Value for Money, Trust. Those do it for me.

But everyone I've spoke to so far say that these particular glasses are
pretty good... even the indepedent commented how they're really nice
frames... I said "Yeah, I got them for £40"

- quote -

Put in the conversion ratio if you're working in dollars... Then the
lowest price for Specsavers is $39 * 1.8 = $70.

My local specsavers just had installed all the latest computer technical
wizardry and performed a more complete array of tests including glaucoma
and something looking at a balloon, which is something the smaller
optician never did. Their service and support has always been excellent
too for me, even doing the usual writing letters for my GP for
investigation of various issues.


- quote -


So far, I've had a better experience at Specsavers... I was never
hassled into getting glasses, I was given a prescription as I walked out
the door with time to think, and the opportunity to go elsewhere, I
wasn't given pressure selling tactics, I was given the opportunity to
ask questions... the only thing the independent did differently, was
that they actually performed less tests, but included one other one
which Im sure is probably available on the computer system at specsavers
somewhere...

Dunno if you're in the UK, as far as I know, we pay £20 for an eye test,
and I think that is fixed across all opticians, and we should be under
no obligation to buy glasses from any particular place. Perhaps that's
why it's not so good using an independent, because they'll try and force
you to buy a pair of expensive glasses so they can increase their profit
margins.

It's not that I necessarily want to buy a useless pair of glasses, or a
cheap pair of glasses, I just want to know if that £60 lens, is the same
as the £40 lens at Specsavers! I think it would be.

- quote -

To be fair, Specsavers are my usual optician. They're an optician I
trust, I only went to the independent after advice from my GP. The
recheck issue is something I wasn't aware of. I didn't realise if
they've misdiagnosed your prescription, that you're necessarily entitled
to a change. But yes, that's a good reason for me staying where I am
then...

Cya
Simon

Dan Abel wrote:
- quote -

Oh don't get me wrong... there are priorities with everything in life...
and if I had any kind of medical issue that required money, that would
be my first priority... but, here, Im just talking about a pair of what
would essentially be reading glasses, that could work probably just as
well as a £200 pair, the only difference is the frame isn't designer,
and I don't have fancy tints and lens options, but if they work then I
would consider spending more at a later time when it becomes more
necessary to use them longer than a couple of hours a day.

Also there's an issue is that the smaller independant retailers probably
aren't as cheap as some of the more well known chain opticians... and
frankly, the eye test there included more tests... it just didn't
include the fixation disparity test... probably because six months ago,
I didn't have the symptoms. All Im saying is, why spend £60 for
something you can get for £20? Though if Im going to be getting
something of higher quality... then I would pay it.

Also the issue for me, with an underactive thyroid, I don't particularly
want to spend exorborant sums of money for an eye problem that might
very well just be temporary.

- quote -

That's it exactly... why spend £200 on something you could get for
£39... There's even a factory outlet store where I live offering glasses
for about £20... And who says that the £60 lenses are of higher quality
than the £40 lenses!

Cya
Simon

There are several aspects to the frame thing. First, quality. Many
stores are happy to sell goods that are made from inferior parts. The
metals corrode, the welds are done badly, the hinges are cheap: in
essence, they are not made to last, they are made down to a price.

Second is the appearance: cheap frames look cheap. If that's how you
want to look, so be it, but not for me. I want my customers coming back
and selling cheap ugly glasses isn't what will do it.

Thirdly is the margin. Specsavers may be happy to sell glasses for next
to nothing, but they will also be paying low wages and provide poor
service and support. I just spent over $100,000.00 on 2 new cameras and
a visual field screener. How many pairs of $39.00 specs do I need to
sell to cover the lease on these???

Ultimately, you get what you pay for. If Simon wants to look after him,
Specsavers isn't the place. But Simon wants the best of both worlds. He
wants an optometrist to spend hours working out the correct
prescription, then go and buy cheap glasses elsewhere. How is it going
to go when his glasses are not quite right and he needs to go back to
the optometrist for a recheck, then go back to specsavers for and
change in script???

dr grant

In article <3utevhF12tsodU2[at]individual.net> ,
Simon Dean <sjdean[at]simtext.plus.com> wrote:

- quote -


Some of us value our vision quite highly. My first retinal detachment
cost almost US$10,000 to fix. It was worth it. The alternative was
going blind in that eye.


- quote -

I don't understand the frame thing. A little plastic, or a little
metal. I was very heavily dependent on glasses for a long time. I'm
now heavily dependent on reading glasses, but they are OTC. I pay
US$18.99 at Costco for a three pack. I get three pair of lenses and
three frames. They work just great.

--
Dan Abel
dabel[at]sonic.net
Petaluma, California, USA

Mike Tyner wrote:
- quote -

Well if that's the case, and I am quite adament I don't have such a
large strabismus, I know for a fact I don't see double (though i can do
that at will as I please), why have they said I should go with "four to
eight" something... in reference to prism lenses...

Thanks
Simon

"Simon Dean" <sjdean[at]simtext.plus.com> wrote

- quote -

Not exactly. Think of FD as a tiny strabismus without diplopia, an angle
small enough that the images are still percieved as single but yet not quite
aligned on the fovea. It's measured in minutes of arc, rather than degrees
or prism diopters.

-MT