A couple of things which turnout to be way older than you thought, courtesy of a visit to the Archaeological Museum of Rhodes. Dating from around 700 BCE: magnifying glasses and cheese graters. I was actually stopped from photographing them (oops); but here are a couple of interesting cites.
An interesting finding from Ialisos, dated between the 7th and 6th centuries BC, consists of a series of three magnifying glasses made of rock crystal and set in decorated bronze frames. The lenses, of different dioptric power, are flat-convex and have a diameter of about 1.5 cm. It is perhaps the oldest known magnifying glasses. They were probably used for jewelery work and for engraving seals.
(Source)
And regarding the grating of cheese, this image of a man grating cheese twenty five centuries ago is from reddit. The source appears to be page 212 of this PDF virtual museum
I have not yet been able to resolve this conundrum: do the magnifying glasses predate the (local) invention of glass?
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