I'd be grateful if anyone could offer some thoughts on my little problem.

With the sunny weather I thought I'd finally get some prescription sunglasses. I settled on some react to light lenses. There was also a buy one get one free offer so I had the same frames with a regular lens. I didn't have a sight test as I'd not long had one at the same place.

When I tried the new react glasses on they appeared wrong, making everything appear as if I was looking through a fish bowl. The second, free pair were better but not perfect. Neither pair are even similar to my current glasses of the same prescription.

I did question the issue and the assistant (there wasn't an optician in) tested all three pairs and said they measure the same.

I'm waiting on a call to discuss the problem but I could do with some pointers as the assistant didn't fill me with confidence.

So far my thoughts are that they are wrong and the assistant is incompetent. Or that the lens are machined off centre some how? I'm not familiar enough to know where and if manufacturing defect could creep in.

If anyone could shed some light that would be fantastic.

Sounds like the perscription is wrong or the centers are out.

Do you know what your old perscrition was and what the new perscription is?

I don't I'm afraid. Though all three pairs of glasses should have exactly the same prescription in; my current pair and the two new pairs.

Are you long or short-sighted? If long -

First thing is a basic test of focal length.

Select a small light source (sun, or a light bulb), and hold up your old glasses to form an image on the floor. Move the glasses up and down until the image is sharp. Estimate or measure the distance from lenses to image.

Now do the same with the questionable glasses. Measure the distance from lens to sharp image.

They should be the same. Unless, of course, the prescription you obtained fairly recently was both:

a) wrong

and

b) not used to produce your old glasses.

Let me know what you find.

If short-sighted, you can't measure their strength with that method, because they won't form an image. But you can still get a rough indication of whether they are about the same as your old glasses.

Just hold the glasses at arm's length and observe a clearly defined object through them. Now do the same with the new glasses, and the images should be the same size, and not twisted around or distorted.

It will be the axis in the glasses that is off then.

You have got astigmatism and they have probably got it slightly off (Thats why the 2nd pair is a little better)

Just take them back and they should sort them out for you.

I'm thinking that if looking through them is like looking through a goldfish bowl there must be more to it than that. We'll have to await further details.

Coffee:

If there are supposed be be the same perscription and 1 pair is worse then I would say that the axis is off in that pair.
You will never know anyway becasue you won't be told but when you take them back it will be one of two things.

If the glasses are taken away and checked(will take 30 sconds) and you are told there was a problem then they were made wrong/off axis/pd's out.......

If you need a re test then the perscrition has been done too strong/weak and they will need to be made again.

Lots of variations without seeing the before and after perscrition and frame choice/size but I'm still saying off axis

I do indeed have a slight astigmatism and need the glasses mostly for distance. Andy would the axis be something that would be easily noticeable when they measure the glasses? I'm a tad concerned as the assistant was adamant that they were correct, almost quite rude about it.

Enforcer, I left the glasses with the store. They really are no use to me as they are. I will however have a try of your test when they come back. I'd be interested in the % deviation they work to and my ability to notice.

Thank you both for your input

I don't think I need a re test. As the glasses on my head now are only a 6 months old. The two new pairs should be to that prescription also.

Yes when the glasses are checked they can see the axis (against your perscription)

Yes there is a tolerance for the axis to british standards
Depending on what you axis is?

But some people still will find it strange if they have a change (again depending on the powers)

Low cly axis is say 15 degrees (0.25) but if you have 2.00 cly it will be 1 degree tolerance.

I'm sure they will sort them for you but I know it can be a pain when something is not correct and you keep getting told they are ok.

Shame your not near to me and I could have looked for you

Well for my money seeing things through a fish bowl is more than astigmatism, but who knows?

Unfortunately, as you are short-sighted the first test is not available to you, unless you also happen to have a weak magnifying glass you can hold in contact with the glasses lens. The second test is not very accurate.

I suppose if they come back to you again like this you will have to take the glasses and prescription to another dispenser, and see what they find.

Thanks again guys. I do hope they sort this sharpish as I've generally been quite happy with the store (although I suspect that it is more to do with convenience as it is in my local supermarket :D).

I'll post up the outcome. If they ever call me...