mid-distance eyeglass lenses -how to work out Add accurately?

[geoff]

In message , chris French writes

Lob your prescription down here, I'll see what glassesonspec can do

[djc]

I tried varifocals once. Very expensive (~£400) and I've never been able to wear them comfortably. I have reading glasses and computer glasses.

My eyes have changed over the years so these days I no longer need them for distance. And the long term effects of a detached retina means glasses make little difference to the blur I see through my left eye. So the varifocals never added much to my distance vision and for close work the need to keep moving my head when reading etc made them uncomfortable. I was persuaded to try the continuous type with no line between the lenses, which I thought would provide an intermediate range for computer work, but it was impossible to hold my eyes/head in such a restricted position. I only tried them for driving once -I thought it would be useful to be able to read a map etc without having to swap, I found them downright dagerous; no peripheral vision so constantly having to turn my head. Even walking down the street and crossing the road felt uncomfortable.

[dennis]

I use varifocals for driving and have no problems with peripheral vision. The distance portion crosses the entire lens, just as with plain lenses. The mid distance is most of the lens. Only the reading bit is noticeably narrow at the very bottom of the lens. The lenses I have are quite an old design and there are better lenses with spherical/plain fronts and all the cylinder on the rear surface these days. I will try those as they are just as cheap at ads as the old designs I have on.

If they did restrict your peripheral vision while driving, you either have an odd prescription or they were wrong.

As for peripheral vision while driving.. have you noticed how many people drive in those stupid glasses with the really thick arms in the centre of the lenses.

[Bob Eager]

But it's possible to adapt - I just move my head a lot and make sure I use the mirrors.

[geoff]

I just don't seem to have any problems, except that I now take my glasses off for close work