Johnson Johnson is the hero of a series of mystery novels written by Dorothy Dunnett (originally published under her maiden name, Dorothy Halliday). Johnson Johnson is a widowed portrait painter who doubles as an agent for the British secret service. A constant theme in all the novels is his yacht, the Dolly.
Each book is told in the first person, from the viewpoint of the heroine, and opens with a comment on Johnson Johnson's bifocals.
References
Johnson Johnson Wikipedia(Text) CC BY-SA