I am about to get my first pair of spectacles. From where I am, glass lenses need a frame. Fiber-plastic lenses can be frameless. It's well known Fiber lenses are much more durable and longlasting. However, between the two, which is more sustainable ? I am hoping to take good care of glass lenses so as not to break. I know glass doesn't decay and the glass industry may have people in hazardous environments.
p.s. Assume, "not wearing spectacles" or "doing eye exercises" are not good enough options.