What does "lay eyes on" mean?

Also, clap or set eyes on. Look at, see, as in As soon as I laid eyes on him I knew he would be perfect for the lead in our play, or I'd never set eyes on such a beautiful gown. The first term dates from the early 1200s and the third from the late 1300s; the second, using clap in the sense of “a sudden movement,” dates from the first half of the 1800s.