GrantC wrote: > > Michael S wrote: > > > > > > Also, does anyone know if there is any reason this style of glasses > > might be harmful or inefficient, or why they fell out of vogue? > > You're new to this planet, right? <grin> They simply aren't > fashionable (at least in the U.S.) these days, that's all. The fashion > right now is for those ugly narrow rectangular things, so I suspect > it'll be a while before rounds come back.
Round-lensed glasses look particularly stupid if the lens spacing doesn't closely match your eye spacing. When I wore little Artcraft Submariners many years ago, I looked walleyed and weird because my eyes were spaced so much wider than the lenses of my glasses. Ovals or rectangles are generally more forgiving in this regard. There is also an optical reason that round lenses are problematic: The frame does not naturally enforce a given orientation upon the lens. For a prescription with astigmatism, rotating the lens is disastrous. For multi-focal or progressive lenses, loss of orientation is likewise a big problem. But even for simple single- vision spherical lenses, rotating the lens in the frame will usually cause the optical center to move, essentially changing the pupillary distance and height. Round lenses make it impossible to distinguish the left lens from the right on cursory examination. If you get truly round lenses, make sure they are marked on the edge and that these marks correlate to some feature on the frame, or else your prescription will be spoiled the moment the lenses are removed from, or rotated within, the frame. Chalo --~--~---------~--~----~------------~-------~--~----~ Check us out at the oft-updated http://glassyeyes.blogspot.com! You received this message because you are subscribed to the Google Groups "GlassyEyes" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/glassyeyes?hl=en -~----------~----~----~----~------~----~------~--~---
