My BIL had and used many sayings, one of which is in very common use and my comments come under the heading, "That's one darn fools opinion." That bit about not replacing only one lens is a hoot. We did it in my office. What they are saying is that their opticians are not good enough to give you a second lens that will match the old lens. Now that I have said that, I will add that it is safer to get lenses by the pair since most opticians today are really sales people not really optical people (even though they think they are). They have had some optical education. However, selling optical, explaining features and benefits of certain lenses and frames is what they read about in the journals and the classes they attend at conventions.
There are several companies that manufacture top quality, no-line, lenses. There are lots and lots of companies that manufacture lenses that are OK and lots and lots more that manufacture bottom end quality. Varilux was one of the top companies when I was in practice; beware because it has been lots and lots of years since I had any say about lens design in general, or for specific types of activities so my info is obsolete.
"In my day" good lens blanks were molded on one surface; the "personal" part of the Rx was ground into the other surface (there were also poor lenses made this way). The really, really good no-line lenses were made with lasers. The use of lasers instead of molding and/or grinding allows for vastly superior lenses if they are fit correctly to the patient's eye position...in relationship to the eyes (how far off of level are the eyes, how far from where the frame fits the nose is each eye) and a bunch of etc.s. The laser cut lenses compensate for what the eyes do when they look to the sides, up and down. All ground and polished lenses are optimum when you look through the "optical centers."
Please understand that an "optician" who has not had classes and studied the properties of these lenses can take these excellent, expensive, lenses and make them function like ordinary lenses. I have not paid any attention to eye pathology, examination techniques for optical devices, lens manufacturing techniques, etc. since I retired. At that time I could legally hire you to be my optician and start you working today with no optical training and no supervision. In other words you could be a carpenter this morning and an optician this afternoon; it was much more difficult to become a hair stylist.
Give me a call at your convenience. If you lost my number, PM me.
Last edited by Jim C Bradley; 08-03-2015 at 03:27 AM.
First of all you have to be smarter than the machine.