Issues with Essilor 1.67 lenses

[mike-uk]

Hi

I've just had a pair of Lindberg rimless specs reglazed in the UK as the coating on the original lenses was flaking off. The lenses had also gone yellowish. I originally bought the specs in 1999 in the USA as a spare pair, but started using them 3 (I think) years ago as my main pair and, although the prescription was not perfect, I wouldn't have replaced the lenses if it weren't for the flaking problem.

Anyway ...

I know that in 1999 I went for the highest index the optician had available, which I believe was a 1.67. So, after getting advice on chromatic ab issues (http://www.optiboard.com/forums/showthread.php?t=14865), and seeing what was available to me (Essilor - which the optician said may actually be Nikon - 1.67 or Hoya 1.7) at the new opticians, I eventually chose to go for another pair of 1.67 for these specs. Basically, I decided that I didn't want lenses that are much thicker for everyday use (so 1.54 Spectralite was out) and there seemed to be very little difference in Abbe between the others, at 32 and 36. And I would also take contacts for times when I really need low chromatic ab.

Unfortunately the specs have come back and I'm having problems with them. Frankly, the lenses seem significantly inferior to the old lenses. Could anyone offer any advice on possible causes and solutions please? The problems are:
a) although I get nice sharp vision when looking through dead centre of the lenses, even tiny deviations from this cause really noticeable blurring. Far more than with the old lenses or with an old pair of Hoya glass lenses I tried. This is no problem with abstract patterns/shapes but is unpleasant with text. For example, I'm typing this on a laptop and in order to avoid quite objectionable distortion I need to centre on the very bottom of the display so that neither the centre of the display (where I am typing) nor the keyboard are over-distorted. The "sweet spot" in the centre of the lenses seems to be vastly smaller than on my previous lenses. Of course, the previous lenses were an old prescription so everything was slightly blurred bu I think the old lenses outperformed the new ones fairly quickly off centre. I thought maybe this is an issue with poor centering, or with the change of prescription (my Sph has improved and I think my astigmatism was apporx 90 in each eye whereas I am now something like -7.5,-1.25,168 and -5.75,1.75,7) but manual shifting of the lenses doesn't seem to help, and I woul dhav ethought my eyes would have settled to the new prescription by now.
b) I am getting noticeable reflections inside the top and bottom edges of the lenses in conditions with artificial lighting. So, right now I am sat under an indoor light fighting and, if I move my hand under my nose I see it reflected (well, I see a flesh coloured shape reflected) on the inside of the top surface of the lenses). If I walk under streetlights I get curved reflections inside the bottom edge of the lenses. And if I stand under an artifical light the light is focused through the lenses, perpendicular to my sightline, producing bright spots 4-5 cm below my specs, on my cheeks. All of this is very irritating and aesthetically "unpleasing". Also, looking from the side I can see the 5-7 curves through the lenses that I last saw with bog-standard glass when I was a kid. My previous lenses had quite roughly faceted edges but these new lenses are very neatly, and even shiny, edged. Could it be that they haven't "roughed up" the edges enough, or is the more likely to be a problem with ineffective coatings or the material of the lens?
c) Generally I am getting a "fuzzy" feeling, as though my eyes are straining. It is a similar feeling to that I get a few days before a migraine. And the right eye (-7.5 prescription) is the worst. When I look in the mirror the right lens appears not to be centred over my pupil, even though I'm sure it was with the old lenses. The glazers have certainly done some tweaking to the bridge as the legs now point inward when resting on a table top whereas they used to be parallel. I know I need to get this sorted at the opticians.

Sorry for the length of the post and for leaving any crucial info out if I have done.

Basically, could anyone suggest please whether the problems I am having are likley to be caused by:
a) inferior lens design (basic lens and/or coatings)
b) prescription problems; or
c) incorrect fitting/manufacture by the lens supplier/glazer

All the best! And thanks in advance for any and all help :-)

Mike

[Pete Hanlin]

It seems like you should return with your new lenses to the optician from whom you purchased them. There are various explanations for each of the problems you describe (i.e., peripheral blur, reflections, fuzzy vision), but the best person to address these issues is your optician.

I would suggest paying another visit to your optician so s/he can address the difficulties you are having with your current lenses. In general, the hardcoating on the lens is not going to affect your vision (and your six year old former lenses probably failed due to a coating issue- assuming you had anti-reflective lenses, that coating could have been supplied by either the manufacturer of the lenses or the laboratory who applied the AR).