The sun is blocked out due to air pollution but one of the characters wears sunglasses anyway and sets a trend. Probably a children's book or story. Published before 1992.
This is the story, Jill Wants Sunglasses by Elizabeth Levy.
This story is found in a school textbook by Holt. The textbook is titled Special Happenings and it has been found in many editions of the textbook, the earliest I found was in 1973. This textbook included many stories meant for grade 3. I cannot locate a copy of the story itself, but below is the best summary I could find from a child’s website project on this story.
The story takes place in 2275 AD. After years of people not caring about pollution, the sun is completely blocked out. People live in apartments in huge, multi-thousand story buildings. Jill is a young girl, who is very obedient. Jill isn't spoiled and only has one request. After looking at old photos and magazines, she wants sunglasses. Although no one has known what sunglasses are for generations. Behind her back, everyone thinks that Jill is crazy. But her parents just wait for this phase to pass. It does, and months go by. One day her father sits and talks with her. He asks what sunglasses were, since its not a touchy topic anymore. Jill explains about sunglasses, and about the sun, which no one has seen for over decades. Since her dad realizes that sunglasses are actual things, they spend years tracking down pairs. So Jill and her dad get pairs of sunglasses, and no one longer thinks Jill is crazy.
According to this Primary Teacher's Guide to the Use of Basal Reader Stories for Teaching an Awareness of Career and Consumer Education Goals document from 1975, the story is 10 pages long.