Gaol pronounced jail if you’re unfamiliar. I’m guessing The Clink. In jails/gaols there previously wasn’t any torches or oil lamps or anything (note: you can’t have a smokeless torch put in a room on tv they’re gas lamps) so it was just really dark if there was no window, which if you’re in a jail in the basement there wasn’t. After a while people’s eyes would entropy from lack of use.
Image: Robert Catesby looking fancy and standing in front of a Stage Door in the top left corner, and in the bottom right corner he’s in Gaol, looking grumpy and messy.
Text: Imprisoned by Queen Elizabeth I after taking part in the failed Essex Rebellion (The Essex Rebellion was a posh rebellion inside of London which included a cue in a showing of Richard III)