Bach is the creator of website Optical Illusions & Visual Phenomena, which began receiving over two million hits a day in 2005.

[4] In 1981 he moved into a full-time position in the Department of Ophthalmology, rising to Professor in 1998, and being appointed as Head of Section Visual Function/Electrophysiology at the University Eye Hospital in 1999.

One strand of his research has been to develop tests of visual acuity, using verbal responding[10][11] or using brain activity.

[12][13][14] As of April 2021, Bach has published 356 scientific papers that have been cited 16602 times, giving him an h-index of 61.

[17] He did not appreciate how popular the site was until he discovered that his internet service provider had suspended his account after it received more than one million hits per day.