Recommendations for High Street Opticians?

[stevensfo]

If the vision needs stronger lenses to correct it, they will either be thicker at the thickest part, or be made of a material with a higher refractive index, so it bends the light more, can be made thinner (for the same strength) and lighter, but which will probably cost more.

I think that for anyone who has worn glasses for more than 40 years knows, this is the standard marketing ploy to make you part with your money. After so many years, there should be only one type of lens. I have the impression that Opticians haven't really changed since the 1980s.


Steve

[Lootman]

You've actually helped me remember something that was bugging me since joining this thread. I could remember having an eye test a few years ago were they used something other than a "puff machine" to test for glaucoma and I remember thinking "this is a nice change, far less intrusive". I now remember it was a "proper" eye doctor that did that test, a doctor at Moorefield Eye Hospital

There are to my knowledge three ways of testing eye pressure:

1) The puff test you mention which I hate and have not had for years.

2) One where an anaesthetic drop is put onto your eye and then some kind of pressure pad touches the cornea and reads the pressure. You don't feel anything and all you see is a blue light.

3) There is a new device from Finland that very gently "stabs" the eye (sounds much worse than it is). Again, painless.

My eye doctor uses the last two to cross check each other. It's not a "test for glaucoma" as such - merely a test for one possible symptom of it. Particularly if you have a thick cornea, as I do, high pressure is not necessarily a problem. A history of peripheral vision tests is a really important clue as to whether you have glaucoma or not, as it is quite hard to diagnose with 100% certainty.

[Julian]

If the vision needs stronger lenses to correct it, they will either be thicker at the thickest part, or be made of a material with a higher refractive index, so it bends the light more, can be made thinner (for the same strength) and lighter, but which will probably cost more.

I think that for anyone who has worn glasses for more than 40 years knows, this is the standard marketing ploy to make you part with your money. After so many years, there should be only one type of lens. I have the impression that Opticians haven't really changed since the 1980s.


Steve

I disagree. I've been wearing glasses for about 50 years. I don't remember the prescription I started out with as a 9 year-old but presumably it was relatively weak (for short-sightedness) and it got as high as -6.25 a few years ago but my short-sightedness has actually been getting better over the last few years and as of last week is now down to -5.25 on my strongest eye (still -5.75 on my weakest). I can assure you that even at -5.75 the thinnest plastic lenses that I found (1.74 refractive index) are a godsend and without that my glasses look like bottle tops. I speak from fairly recent experience.

A couple of years ago I got some prescription sunglasses from an online optician and chose the 1.6 option (lower refractive index numbers are thicker). The optician had an offer of a free second pair but it was only free if it was one of their cheap own-brand frames with standard thickness lenses. Since it was free I thought I might as well get a simple plain pair of emergency glasses with the standard (free) 1.5 refractive index. They look dramatically different in thickness to my main 1.74 refractive index high street glasses and on the one occasion when I did wear them for a couple of weeks when my main pair was in for a reglaze a couple of different people who have known me for decades wearing thin lenses immediately commented on the thickness.

Now, your retort might well be either a theory or knowledge that all these lenses cost pretty much the same to make regardless of thinness so premium-pricing the thinner lenses is the rip-off. Firstly, if that is a theory then I very much doubt that is true; I would imagine that the manufacturing process is more complex and tolerances are finer on thinner optics. Even if it is the case though an optician would still need to carry lenses in different refractive indexes because this is not a "one size fits all" situation. The 1.74 lenses will always be needed for people like me with strong prescriptions however if that was the only refractive index available then the lenses made for people with weaker prescriptions would be too thin to cut the required groove for wire-rimmed glasses and too thin and flimsy to maintain integrity around the drill holes for wireless frames. I'm afraid the choice is absolutely necessary and, although I wouldn't be at all surprised if the margins might be higher on the higher refractive index lenses, I suspect there are also genuine differences in manufacturing costs that at least partially account for the differing prices.

On the lack of change since the 1980s bit I would also disagree. As someone who has worn strong lenses for a while I can say that opticians, or at least the range of lens options available to them, have changed significantly even in the last decade. Given that I have needed the thinnest 1.74 lenses for a while there are options available to me now that simply weren't there a decade ago (or maybe 15 years, I forget exactly) for instance tints (sunglasses), transition lenses and I think even varifocals have not always been available options for the thinnest lenses but they are now.

I actually wonder if there is further still to go. Unless things have changed in the last few years I think going above 1.74 refractive index involves a switch to glass which increases fragility and weight. (As a psoriasis sufferer the weight is also a big issue for me.) I would certainly welcome a future development that allowed me to go up another step in refractive index while staying with plastic lenses.

- Julian