Contrast

Contrast is not always black and white.

Full marks to the opticians and technicians at Opera Opera in Covent Garden (apologies for picture of David Starkey).

Not only did they fully explain my 'unusual' optic nerve (thanks Western Eye Hospital, the word is 'inverted') but they fitted me with some great specs which optimise my field of vision. Shallow specs are no use if you wear varifocals, but high street opticians don't bother to tell you this.