Here I recreate an early experiment in corrective optics. The science of optics began with Abu Ali Hasan Ibn Al-Haitham (aka Alhazen) around 1000 AD. Based on his work, early mediaeval  reading stones and glasses appeared in Europe around 1200, using beryl (or quartz) crystals as the lens material. The German word for spectacles remains to this day Die Brille (from beryl). Note the well-curated beryl crystals with their nice little museum numbers. Designer frames by Ralph Jefferson, Leicester University.