Optical zones for contacts 
Author Message
 Optical zones for contacts

I started wearing contacts just over a week ago, and now have one
sample pair each of Acuvue 2 (AV2) and Focus Night & Day (FND).  I
will likely get a sample of Acuvue Oasys when I go back sometime this
week (I work on a computer, and the CRT monitor has a fair amount of
drying power).

I'm interested in doing extended wear for a few days at a time, as the
mood suits, which is why I'm trying the FND, but there's something
more important to me - night vision.

I'm an amateur astronomer, so night performance is pretty important.
More than that, since not having to deal with the hassle of glasses
when using binoculars or a telescope is one of my main motivations for
getting contacts (the others are comfort, vision correction, and all
the annoying ways in which stuff gets on glasses - rain, sweat, etc.).

I noticed last night that the FND lenses did not produce sharp images
of stars, or any light source in the dark.  After doing some blinking
and nudging to see if I could get a better image out of them, I
removed them and put the AV2 lenses in.  While I still get halos
around light sources in the dark, star images look sharp - much
sharper than they ever did with any pair of glasses (managed to spot
Pleione, Celaeno, and Asterope in the Pleides, with a 3/4 moon under
normally mag 6.0 skies, if any of you know understand the significance
of that).

Since then, I've been trying to find information on the size of the
optical zone of these lenses (and AVO, since I'll be trying them as
well).  I figure they must be too small to correct all rays entering a
dark-dilated pupil.

But I can't find that information anywhere.

Does anyone know where I might find a list of various lenses with
their optical zone sizes?

Beyond that, I notice that the Acuvue Oasys lenses have an oxygen
permiability not much less than Focus Night & Day, and are also made
of a silicone hydrogel.  Am I correct in guessing that they'd be just
as good as FND for several-day extended wear, with proper rest and
lens cleaning between wearing sessions?
--
 - Mike

Ignore the Python in me to send e-mail.



Fri, 27 Feb 2009 21:01:52 GMT
 Optical zones for contacts
You can wear them, but take them out before going to sleep. Stick with
glasses for the computer. Use contacts for astronomy


Sun, 01 Mar 2009 10:26:21 GMT
 Optical zones for contacts
mike

that information is available in a publication called Tyler's
Quarterly.  It is also available in a website at
http://www.eyedock.com/index.htm (search under contact lenses under
advanced search).

the idea of the cause of the halos you see is plausable but no the only
explanation.  for example, perhaps you have some uncorrected
astigmatism with your contacts on.  also, perhaps you might benefit
from a lens with an aspheric design.  go to your contact lens fitter
and ask for their opinion on lenses you might try.  you are more likely
to find success since your fitter knows as much about contacts as you
do about astronomy/telescopes.  we deal with these halo complaints all
the time.

---------------------

Quote:

> I started wearing contacts just over a week ago, and now have one
> sample pair each of Acuvue 2 (AV2) and Focus Night & Day (FND).  I
> will likely get a sample of Acuvue Oasys when I go back sometime this
> week (I work on a computer, and the CRT monitor has a fair amount of
> drying power).

> I'm interested in doing extended wear for a few days at a time, as the
> mood suits, which is why I'm trying the FND, but there's something
> more important to me - night vision.

> I'm an amateur astronomer, so night performance is pretty important.
> More than that, since not having to deal with the hassle of glasses
> when using binoculars or a telescope is one of my main motivations for
> getting contacts (the others are comfort, vision correction, and all
> the annoying ways in which stuff gets on glasses - rain, sweat, etc.).

> I noticed last night that the FND lenses did not produce sharp images
> of stars, or any light source in the dark.  After doing some blinking
> and nudging to see if I could get a better image out of them, I
> removed them and put the AV2 lenses in.  While I still get halos
> around light sources in the dark, star images look sharp - much
> sharper than they ever did with any pair of glasses (managed to spot
> Pleione, Celaeno, and Asterope in the Pleides, with a 3/4 moon under
> normally mag 6.0 skies, if any of you know understand the significance
> of that).

> Since then, I've been trying to find information on the size of the
> optical zone of these lenses (and AVO, since I'll be trying them as
> well).  I figure they must be too small to correct all rays entering a
> dark-dilated pupil.

> But I can't find that information anywhere.

> Does anyone know where I might find a list of various lenses with
> their optical zone sizes?

> Beyond that, I notice that the Acuvue Oasys lenses have an oxygen
> permiability not much less than Focus Night & Day, and are also made
> of a silicone hydrogel.  Am I correct in guessing that they'd be just
> as good as FND for several-day extended wear, with proper rest and
> lens cleaning between wearing sessions?
> --
>  - Mike

> Ignore the Python in me to send e-mail.



Sun, 01 Mar 2009 19:44:18 GMT
 Optical zones for contacts

Quote:

> Does anyone know where I might find a list of various lenses with
> their optical zone sizes?

Answered already

Quote:

> Beyond that, I notice that the Acuvue Oasys lenses have an oxygen
> permiability not much less than Focus Night & Day, and are also made
> of a silicone hydrogel.  Am I correct in guessing that they'd be just
> as good as FND for several-day extended wear, with proper rest and
> lens cleaning between wearing sessions?

You are correct.


Sun, 01 Mar 2009 21:07:37 GMT
 Optical zones for contacts

Quote:

> You can wear them, but take them out before going to sleep. Stick with
> glasses for the computer. Use contacts for astronomy

Quit giving advise without any knowledge of the topic.  why should he
wear contacts and not glasses for astronomy?  did he ask that questions
anyway?  did he ask for opinions about extended wear contact lenses?
why wear glasses for computer work and not contacts?  on what basis do
you answer these questions?  experience or expert training (or
delusional egotistical thinking)?

explain the reasons why you make a suggestions and it better be more
than "thats what i read on some bulletin board or some website" or
"thats what my daddy said".



Sun, 01 Mar 2009 21:12:25 GMT
 Optical zones for contacts
On or about 13 Sep 2006 04:44:18 -0700 did "retinula"

Quote:
>mike

>that information is available in a publication called Tyler's
>Quarterly.  It is also available in a website at
>http://www.eyedock.com/index.htm (search under contact lenses under
>advanced search).

Thanks for that link.  Unfortunately, both Focus Night & Day and
Acuvue Oasys have "unknown" optical zone sizes.

Acuvue 2 is listed at 8mm.

Quote:
>the idea of the cause of the halos you see is plausable but no the only
>explanation.  for example, perhaps you have some uncorrected
>astigmatism with your contacts on.  also, perhaps you might benefit
>from a lens with an aspheric design.  go to your contact lens fitter
>and ask for their opinion on lenses you might try.  you are more likely
>to find success since your fitter knows as much about contacts as you
>do about astronomy/telescopes.  we deal with these halo complaints all
>the time.

At the time of the exam, he said I had no more than +0.25 astigmatism
in each eye.  So perhaps an aspheric would help.

I will, of course, discuss this with the optometrist.
--
 - Mike

Ignore the Python in me to send e-mail.



Tue, 03 Mar 2009 14:35:07 GMT
 Optical zones for contacts

dribble thusly:

Quote:
>You can wear them, but take them out before going to sleep. Stick with
>glasses for the computer. Use contacts for astronomy

While searching past messages in this group, your name came up in many
threads.  I've yet to see a sensible or knowledgeable post attached to
it that wasn't a quote of someone else.

I've been wearing glasses for 21 years.  I decided to try contacts
because I'm tired of glasses.  

Tired of the weight, the glare, the restricted zone of clear vision,
the fickle correction, the fogged lenses, the rain drops, the sweat
drops from my brow, and many other things.

Contacts don't weigh anything to speak of, have no glare, correct my
entire field of vision, correct it consistently, don't fog up, don't
get rain drops on them (that aren't blinked away in a split second),
etc.

I've been wearing them a few hours shy of two weeks now, and from now
one, the only time I'll wear glasses is when I need to (or should)
take the contacts out for a spell.

Did you perhaps try contacts, and weren't able to adapt?  Did you wear
them too long, and develop an eye problem as a result?  Can't wear
them anymore?  Whatever your motivation, you shouldn't continually
apply your problems or your failings to the eye correction decisions
of others.
--
 - Mike

Ignore the Python in me to send e-mail.



Tue, 03 Mar 2009 14:49:25 GMT
 Optical zones for contacts


Quote:

> dribble thusly:

> >You can wear them, but take them out before going to sleep. Stick with
> >glasses for the computer. Use contacts for astronomy
> I've been wearing glasses for 21 years.  I decided to try contacts
> because I'm tired of glasses.  

> Tired of the weight, the glare, the restricted zone of clear vision,
> the fickle correction, the fogged lenses, the rain drops, the sweat
> drops from my brow, and many other things.

> Contacts don't weigh anything to speak of, have no glare, correct my
> entire field of vision, correct it consistently, don't fog up, don't
> get rain drops on them (that aren't blinked away in a split second),
> etc.

> I've been wearing them a few hours shy of two weeks now, and from now
> one, the only time I'll wear glasses is when I need to (or should)
> take the contacts out for a spell.

One of the reasons that so many people wear contacts is because they
like them better than glasses.  Some people are unable to adjust to
contacts.  I resisted contacts for decades.  I had to wear them for
medical reasons.  My doctor warned me that if they worked and I got used
to them, I might end up preferring them and wearing them when I didn't
need to continue their use for medical reasons.  That was true for me.  
I wore contacts for ten years.  Due to surgery, I now wear neither
glasses nor contacts.  If my eyes were the same as they were back then,
I would still be in contacts.

YMMV

--
Dan Abel

Petaluma, California, USA



Wed, 04 Mar 2009 00:40:29 GMT
 Optical zones for contacts
Hi Mike :),

for some time I had already planned on posting my experiences with the
optical zones of various lenses to this newsgroup.
Unlike retinula wrote, not all contact lens fitters (regardless of being
ophthalmologists or optometrists) have experience regarding this. I've
had both an optometrist as well as an ophthalmologist tell me that there
is nothing that can be done about the problems I had (seeing halos).
Both had sold yearly lenses (Lunelle) to me that have a very small
optical zone. They also insisted that these would be the best lenses for
long wear times (which obviously is not the case anymore, with all the
silicone-hydrogel options - at least if astigmatism correction isn't
needed).
Only by doing my own research I found out what the problem was (by the
way, thanks a lot to all the professionals sharing their knowledge here
and in other places on the net!).

So far I have tested theses lenses: Acuvue Oasys, Acuvue Advance,
Coopervision Proclear Monthly, Bausch & Lomb Purevision, Cibavision
Airoptix and Cibavision Focus Night & Day.

Focus Night & Day seems to have by far the smallest optical zone, though
as you pointed out there is no information available on the internet as
to how big it is exactly.

Bausch & Lomb Purevision have 8.9mm according to eyedock which should be
correct. I still have problems in very lowlight situations

Coopervision Proclear have 9mm according to Coopervision Germany and
contaguide (a highly recommended site, however it is in French. It has
some of the infos that eyedock doesn't have:
http://www.contaguide.com/pro/lentilles.php ). Still getting slight
problems with the optic zone there.

I think that Cibavision Airoptix have a bigger optic zone than Focus
Night & Day though probably smaller than 9mm (note these are subjective
opinions, I haven't got any factual data to back that up with, yet). At
least I still get problems here too.

Acuvue Oasys is fortunately among the lenses that work best for me in
terms of optic zone (unfortunately no data about it available online),
I've been using it a lot, with the occasional extended wear too. In
general it is by far one of the most comfortable silicone-hydrogel lens
(Purevision, Airoptix and Focus Night & Day all have quite a high
modulus which becomes evident already when handling the lenses). However
slight problems with halos remain for me (in very low light
situations). At least going to the cinema is possible for me with
them (though in some lowlight movie scenes I do get halos).
For me Oasys do outperform all other non-Acuvue silicone-hydrogel lenses
in terms of both comfort and optic zone.

Finally Acuvue Advance is one lens where I don't see any halos at all,
so in terms of vision they are a dream. However I can't keep them in as
long as the Oasys ones, especially if I don't have rewetting drops
available. But I still have to test some more to know for sure, but have
to get a new pair as my current obviously didn't like being stored in 3%
peroxide for a longer time.

So for now I guess I'm sticking to Acuvue Oasys myself (and maybe
occasionally Advance) and I would highly encourage you to try them,
nightvision should be a lot better and you will probably like the added
comfort, too.
I'm planning on asking at the various companies for the exact sizes of
the optic zones (however I don't know how much these are also dependent
on the indvidual lens power) and will post again to this newsgroup when
I know more. Also I think it is a good idea to give the companies
feedback - I don't know how many people have these problems (and to what
extent). Soon there should also be the new Coopervision Biofinity Lens
which I'm looking forward to very much. However my hopes for a bigger
optic zone aren't that big.

A big enough optic zone combined with a comfortable silicone-hydrogel
lens would be a dream come true for me (especially as I get some slight
haloing in very lowlight situations with glasses, too. I assume that
this might have to do with corneal abberations present in the outer
regions of the cornea. With Advance I have almost perfect vision).

That's it from me for now. Hopefully this info is useful to someone
else, too.

Andi



Thu, 05 Mar 2009 00:02:59 GMT
 Optical zones for contacts
On or about Sat, 16 Sep 2006 18:02:59 +0200 did Andi

Quote:
>Hi Mike :),

>for some time I had already planned on posting my experiences with the
>optical zones of various lenses to this newsgroup.
>Unlike retinula wrote, not all contact lens fitters (regardless of being
>ophthalmologists or optometrists) have experience regarding this. I've

I saw the optometrist again this past Friday, and he didn't have any
information about the size of optical zones.  It would not surprise me
in the least if this is the case with most optometrists.

Quote:
>So far I have tested theses lenses: Acuvue Oasys, Acuvue Advance,
>Coopervision Proclear Monthly, Bausch & Lomb Purevision, Cibavision
>Airoptix and Cibavision Focus Night & Day.

>Focus Night & Day seems to have by far the smallest optical zone, though
>as you pointed out there is no information available on the internet as
>to how big it is exactly.

>Bausch & Lomb Purevision have 8.9mm according to eyedock which should be
>correct. I still have problems in very lowlight situations

As it happens, though I thought I was given Acuvue 2 initially, I
found out on Friday that I was actually wearing Acuvue Advance.  As
you say, they have pretty good night performance.  But they are
definitely not suitable for extended wear.

I got samples of Acuvue Oasys and B&L PureVision on that visit.

Quote:
>Acuvue Oasys is fortunately among the lenses that work best for me in
>terms of optic zone (unfortunately no data about it available online),
>I've been using it a lot, with the occasional extended wear too. In
>general it is by far one of the most comfortable silicone-hydrogel lens
>(Purevision, Airoptix and Focus Night & Day all have quite a high
>modulus which becomes evident already when handling the lenses). However

I concur completely about the Oasys lenses.  They are by far the most
comfortable of the four I've tried now, and the best for working at
the computer.

The PureVision lenses seem to have very good night vision.  I still
see halos around bright LED's in a dark room, but star images look
very sharp.  I'll need to wait for a good clear night to really give
them proper testing.

They are, however, not very comfortable, and feel much like the Focus
N&D lenses.  Their biggest advantage over the latter is the larger
size, I think, which makes the edges less prominent.

Quote:
>So for now I guess I'm sticking to Acuvue Oasys myself (and maybe
>occasionally Advance) and I would highly encourage you to try them,
>nightvision should be a lot better and you will probably like the added
>comfort, too.

I'm 90% of the way towards adopting them as my standard lens.  I'm
wearing them right now (no problems at the computer), and have had
them in for about 20 hours, with no discomfort.  That includes
sleeping, since I'm currently on a night schedule (I work at home on
the computer).

If the Advance do in fact have better night correction, I might just
keep them around for stargazing sessions.

Quote:
>I'm planning on asking at the various companies for the exact sizes of
>the optic zones (however I don't know how much these are also dependent
>on the indvidual lens power) and will post again to this newsgroup when
>I know more. Also I think it is a good idea to give the companies
>feedback - I don't know how many people have these problems (and to what
>extent). Soon there should also be the new Coopervision Biofinity Lens
>which I'm looking forward to very much. However my hopes for a bigger
>optic zone aren't that big.

>A big enough optic zone combined with a comfortable silicone-hydrogel
>lens would be a dream come true for me (especially as I get some slight
>haloing in very lowlight situations with glasses, too. I assume that
>this might have to do with corneal abberations present in the outer
>regions of the cornea. With Advance I have almost perfect vision).

I'd definitely be interested in what you find.  Given my limited
experience thus far, I'd say any silicone hydrogel lens with a low
modulus and large optical zone would be worth trying.

--
 - Mike

Ignore the Python in me to send e-mail.



Thu, 05 Mar 2009 13:27:26 GMT
 
 [ 10 post ] 

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