Gold and tortoiseshell folding spectacles in a black leather case, made by Baker, an optician in Holborn, London. Spectacles have been used in the West for at least 700 years. The earliest had convex lenses, and they were worn by people with long sight to help them focus on nearby objects. Later, concave spectacle lenses were made for people with short sight. In 1784 Benjamin Franklin (1706-1790) invented 'bifocals' -spectacles split into two parts, each with a different focal length.
© Science Museum / Science & Society Picture Library