Songfacts®:

• In a 1985 interview with Spin magazine, ZZ Top bass player Dusty Hill explained: "We wrote that song when we used to tour in cars. And every gas station in the world had a cardboard display of the cheapest and ugliest sunglasses you could imagine. I have bought a thousand pair of them."
  
  Guitarist Billy Gibbons added: "The hip trip for us was to throw them into the audience as an offering. We ran out and we couldn't get any more. So we now have to make to do with Sanford Hutton's creations out of New York. The Ray Ban Wayfarer was the original cheap sunglasses. You could buy a pair for six bucks originally. I saw a catalog from 1959, and by then they were up to eight bucks. We had to take a bad rap from an optometrist who said 'Don't wear ZZ Top's cheap sunglasses. They're bad for your eyes.' There was an optometrists' convention in Hawaii and there was a huge poster – this woman with a pointing finger saying, 'Don't wear cheap sunglasses.' I suppose I'll have to agree. There is a cutoff point where optical considerations must be taken into account.
  
  However, if you will subscribe to the lyrics:
  
  When you wake up in the morning
  And the light is hurtin' your head
  The first thing you do when you get up out of bed
  Is put on cheap sunglasses
  
  At that point in time, they are not intended to be used for negotiating the entire afternoon."
• ZZ Top took some time off after their 1976 album Tejas. When they returned to action in 1979, punk rock had emerged, emboldening the band to cut loose, with less concern about what FM radio might play. That attitude led to songs like "Manic Mechanic" and "Cheap Sunglasses."
  
  The band also came back with a new look: Billy Gibbons and Dusty Hill had their long, flowing beards for the first time with the album. Gibbons and Hill claim they didn't consult each other before growing them.
• According to Billy Gibbons, the band wrote the song on a trip to Austin, Texas as they were passing La Grange. He came up with lyrics to all three verses in the span of 20 miles.
• Billy Gibbons played the main guitar line through a 200-watt Marshall Major amp with a blown tube, which gave him the "bulbous, rotund sound." He told Guitar World: "There's also a little bit of digital delay for that Bo Diddley impersonation at the tail out, and a Maestro ring modulator, which produces the strange tag to each verse. It appears three times, and it's a pretty funny sound. That is one insane effect put to good use."