I've noticed that prescription eye glasses frames are often made from metal that is quite rigid. It's surprisingly difficult to bend the metal, despite how thin it is. And if it does bend, it doesn't seem to weaken much when bent back and forth.
Is there a certain kind of metal that is typically used for making prescription glasses frames?
Examples that come to mind:
There are many different materials that can be used for modern eyewear.
Based on the following table (I put it together from online searches, its not from a single site, although the content is repeated - also I haven't managed to complete it), probably the ones you are looking at are either:
| description | lightweight ($gr/cm^3$) | strong | corrosion resistant | hypoallergic | cost | flexible | usage |
|---|---|---|---|---|---|---|---|
| Titanium | +++ (4.5) | +++ | + | + | durability | ||
| Monel (usually nickel-copper alloys) | (8.8) | ++ | + (have a coating to protect the skin) | people who spend a lot of time in or around salt water | |||
| Beryllium alloy | ++ (1.85+?) | + | +++ | ++ | people who spend a lot of time in or around salt water | ||
| Stainless steel | + (8) | + | ++ | ||||
| Flexon (Ti -Ni shape memory alloy) | + (6.5) | + | + | + | +++ | active kids | |
| Beta titanium (Ti+ traces Al+V) | ++ (4.5) | + | + | + | +++ | active kids | |
| Aluminum | + (2.7) | ++ | ++ | + | ++ | high-end frames | |
| Magnesium | + (1.7) | high-end frames |
NOTE: the above is not a authoritative table. It is my interpretation from online searches.
