Here's a short story:

Mary David knew she wanted to be a movie star when she was very young. She was not sure what gave her the idea, but she wanted to look like a movie star. "I have a lot of pictures from my childhood of me wearing sunglasses," she says. "I used to wear them to watch TV." Early movie actors started wearing sunglasses, not because they looked good, but because their eyes hurt. The lights used on movie sets were really bright and could cause a painful problem known as "Klieg eyes". It was named after the Klieg brothers who invented the lights. Actors wore sunglasses to give their eyes a rest. But when movie stars began wearing their sunglasses in public, they quickly became a must. From then on, actors started wearing sunglasses in their movies as well as on the street. Audrey Hepburn wore ultra-cool Ray-Ban sunglasses in the 1961 movie, Breakfast at Tiffany's. As a result, Ray-Ban sunglasses started to appear more and more in the movies. In 1979, Ray-Ban "Wayfarers" were worn by Jake and Elwood in The Blue Brothers. Tom Cruise wore Ray-Ban "Aviator" sunglasses in the 1986 hit, Top Gun. Then in 1997, Will Smith and Tommy Lee Jones made Ray-Ban "Predator" sunglasses famous in Men in Black. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: why did early movie actors wear sunglasses?
Guess: their eyes hurt

Question: what did mary david want to be?
Guess: a movie star

Question: what did she like to wear when she was young?
Guess: sunglasses

Now answer the following question in the same format.

Question: what was the name of the painful problem that lights can cause?

Klieg eyes