Geograph - photograph every grid square

My mother and sister had decided to have a trip around the Town Hall, which on Tuesdays includes a look at the Mayor's full regalia. Not fancying this, I decided to see how many shops I could visit in an hour. As always I overran, but luckily so did their tour!

Glasses were being made in 13th century Italy. The idea caught on quickly. They can correct both hyperopia (farsightedness) and presbyopia (long-sightedness). In 1752 James Ayscough created a doubled hinged ear piece; and in 1784 Benjamin Franklin created bifocal lenses. The first optical store was opened in Philidelphia in 1799. In 1825 the astronomer George Airy created the first lens that was used to correct astigmatism. The 20th century saw numerous improvements including contact lenses and laser surgery.