Are $1 glasses harmful?

My Mum who's in her late sixties stocked up on several pairs of reading
and distance glasses at the dollar store. They don't give her perfect
vision but she thinks it's crazy to spend hundreds for the difference
proper prescription lenses would make.

Could these cheap lenses be hurting her eyesight? She doesn't really
complain of headaches, so I'm assuming they're not causing that sort of
problem to her.

In article <(E-Mail Removed) .com>,
"Lady Penelope Creighton-Ward" <(E-Mail Removed)> wrote:

> My Mum who's in her late sixties stocked up on several pairs of reading
> and distance glasses at the dollar store. They don't give her perfect
> vision but she thinks it's crazy to spend hundreds for the difference
> proper prescription lenses would make.
>
> Could these cheap lenses be hurting her eyesight? She doesn't really
> complain of headaches, so I'm assuming they're not causing that sort of
> problem to her.

Best thing to do is to have her ask her OD. My OD told me that OTC
should work for me, despite the vast difference in my eyes at distance.
He looked at my OTC glasses, tested me and recommended a slightly
different power.

He can also advise about using OTC glasses for distance. They aren't
designed for that, but may work for your mother anyway.

Also, she could ask about cheaper options.

--
Dan Abel
(E-Mail Removed)
Petaluma, California, USA

On 10/11/06 8:38 AM, in article
(E-Mail Removed). com, "Lady Penelope
Creighton-Ward" <(E-Mail Removed)> wrote:

> My Mum who's in her late sixties stocked up on several pairs of reading
> and distance glasses at the dollar store. They don't give her perfect
> vision but she thinks it's crazy to spend hundreds for the difference
> proper prescription lenses would make.
>
> Could these cheap lenses be hurting her eyesight? She doesn't really
> complain of headaches, so I'm assuming they're not causing that sort of
> problem to her.
>
Probably they are no more harmful than any other glass object that can break
and introduce glass shards into the eye.

I have difficulty believing that the increase in life expectancy comes from
the replacement of glass lenses by plastic.

Bill
-- Fermez le Bush

I also have several of those pairs that I use as a magnifying glass. I
dont need them because I am myopic so they dont get used much.

Using them for distance and driving? If you can see at least 20/40 with
them, you may be legal. However if $100 prescription glasses correct
you better, spend the money and use the readers for near work.

I also have several of those pairs that I use as a magnifying glass. I
dont need them because I am myopic so they dont get used much.

Using them for distance and driving? If you can see at least 20/40 with
them, you may be legal. However if $100 prescription glasses correct
you better, spend the money and use the readers for near work.

Dan Abel wrote:

> "Lady Penelope Creighton-Ward" <(E-Mail Removed)> wrote:
>
>> My Mum who's in her late sixties stocked up on several pairs of reading
>> and distance glasses at the dollar store. They don't give her perfect
>> vision but she thinks it's crazy to spend hundreds for the difference
>> proper prescription lenses would make.
>>
>> Could these cheap lenses be hurting her eyesight? She doesn't really
>> complain of headaches, so I'm assuming they're not causing that sort of
>> problem to her.

I've used them with my contacts for reading since 1999 with no damage
that I'm aware of. Anecdotes are not evidence, however.

> Best thing to do is to have her ask her OD. My OD told me that OTC
> should work for me, despite the vast difference in my eyes at distance.
> He looked at my OTC glasses, tested me and recommended a slightly
> different power.
>
> He can also advise about using OTC glasses for distance. They aren't
> designed for that, but may work for your mother anyway.

Even if we're farsighted? The +3.5 cheapies work better than my unaided
eye (left needs +5 and nobody sells those), although I really miss the
astigmatism correction. Still, If I had stepped on my glasses and had
to drive to the optometrist's office, they'd be usable.

> Also, she could ask about cheaper options.

--
Cheers,
Bev
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ =+=
"The object in life is not to be on the side of the
majority, but to be insane in such a useful way that
they can't commit you." -- Mark Edwards

Salmon Egg wrote:

> On 10/11/06 8:38 AM, in article
> (E-Mail Removed). com, "Lady Penelope
> Creighton-Ward" <(E-Mail Removed)> wrote:
>
>> My Mum who's in her late sixties stocked up on several pairs of reading
>> and distance glasses at the dollar store. They don't give her perfect
>> vision but she thinks it's crazy to spend hundreds for the difference
>> proper prescription lenses would make.
>>
>> Could these cheap lenses be hurting her eyesight? She doesn't really
>> complain of headaches, so I'm assuming they're not causing that sort of
>> problem to her.
>>
> Probably they are no more harmful than any other glass object that can break
> and introduce glass shards into the eye.

What, you think the Chinese use actual GLASS in these?

> I have difficulty believing that the increase in life expectancy comes from
> the replacement of glass lenses by plastic.

You don't want to hear about how I rode my motorcycle wearing am
open-face helmet and glass sunsensor lenses for decades then...

--
Cheers,
Bev
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ =+=
"The object in life is not to be on the side of the
majority, but to be insane in such a useful way that
they can't commit you." -- Mark Edwards

Lady Penelope Creighton-Ward wrote:
> My Mum who's in her late sixties stocked up on several pairs of reading
> and distance glasses at the dollar store. They don't give her perfect
> vision but she thinks it's crazy to spend hundreds for the difference
> proper prescription lenses would make.

Recently, I downloaded a CD from IPod, and have been listening to it
for awhile. The recording sounded kind of muddy. I should say that I
have a really good system for music playback, four-way speakers,
subwoofers, class A amplifier, etc. Unknown to me, my wife had bought
a copy of the same CD. I could hear the difference in quality,
immediately. There was more depth, more detail, more precise imaging.

Like music, I like my images without ghosts, halos, and chromatic
aberration. Or, let's say I notice them. Many people obviously don't,
but that doesn't mean I'm going to cave in on the quality issue. Big
companies spend millions of dollars to create a better visual
experience.

DrG

On 10/17/06 6:02 AM, in article
(E-Mail Removed). com, "Dr. Leukoma"
<(E-Mail Removed)> wrote:

> Recently, I downloaded a CD from IPod, and have been listening to it
> for awhile. The recording sounded kind of muddy. I should say that I
> have a really good system for music playback, four-way speakers,
> subwoofers, class A amplifier, etc. Unknown to me, my wife had bought
> a copy of the same CD. I could hear the difference in quality,
> immediately. There was more depth, more detail, more precise imaging.
>
> Like music, I like my images without ghosts, halos, and chromatic
> aberration. Or, let's say I notice them. Many people obviously don't,
> but that doesn't mean I'm going to cave in on the quality issue. Big
> companies spend millions of dollars to create a better visual
> experience.

I have purchased second rate recordings at premium prices. It happens. My
experience in London has been that the lower the cost of a meal, until it
was ridiculously low, the more likely the food was to be better.

To the question at hand. The quality of a lens can be measured. I doubt
that ophthalmic lens information is readily available. One good measure is
the strehl ratio which gives the actual intensity achieved for a focused
point of light divided by the theoretical intensity for the same point for a
perfect lens. That includes the effects of aberration, scattering, and
diffraction. Diffraction should not be a problem for optometry. For positive
spherical lenses, that can be measured directly although the methods can be
extended to negative and cylindrical lenses as well.

MTF, modulation transfer function, is also a good measure of quality. It
will quantify the "muddiness" of the optical system.


Bill
-- Fermez le Bush

Salmon Egg wrote:

> I have purchased second rate recordings at premium prices. It happens. My
> experience in London has been that the lower the cost of a meal, until it
> was ridiculously low, the more likely the food was to be better.

Here in Dallas, the quality and the price tend to have some direct
relationship. I think that the price of raw ingredients has some
bearing, as does the overhead. I found the same to be true in London.
I went to top notch restaurants that came highly personally recommended
and as a result was not disappointed.

Where I did not find this relationship was in the many ethnic
restaurants in Chicago. Once an ethnic restaurant "made it big," then
the prices went up. But, then they could afford to charge more, so
long as the quality is maintained. People don't always go out for the
food, they also go out for the experience, atmosphere, etc. I go for
the food.

Then there are people who just like to find the exception just to prove
a point.

DrG