I had worn a biomedics 55 lens at -5.75 strength. Since it was too
weak, I went to the optometrist who offered Ia -6.00 which was still
slightly weak. She said the Biomedics 55 then goes to -6.50 (skipping
-6.25). This is a 'spheric' lens and it's good, but I find it almost a
tad too strong. Is there a reason why biomedics does not produce a lens
at -6.25 ? Karen
Mike Tyner - 29 Apr 2006 00:46 GMT
> slightly weak. She said the Biomedics 55 then goes to -6.50 (skipping
> -6.25). This is a 'spheric' lens and it's good, but I find it almost a
> tad too strong. Is there a reason why biomedics does not produce a lens
> at -6.25 ? Karen
Economy, mostly, determined by the bell-shaped curve of people wearing
contacts.
Other companies like Vistakon do the same thing.
Ciba and B&L offer -625, -675 etc in some of their lenses.
-MT
acemanvx@yahoo.com - 29 Apr 2006 06:51 GMT
many companies go by half diopters starting at -6 because few people
can tell the difference between .25 diopters and also not many people
have such bad vision so it would cost the company too much to make
contacts in .25 diopter steps all the way to -10 or -12. How well do
you see with -6 contacts? If your seeing 20/20(unless you cant be
corrected to that) its the right power. Otherwise use -6.5 then.