Ultrasound is used to map the precise size and shape of the eye so the gunk can be removed and a made-exactly-to-fit piece inserted to replace it!
Amazing technology.
Mine were done in January and February of 1999; outpatient surgery, under an IV sedative. It was so weird to be awake and aware of what was happening - yet totally detached, even knowing what the surgeon was doing! Never felt a thing, and went home after the sedative wore off.
Granted, hers is in a more difficult spot and she'll be watched in the hospital afterward, but a good outcome is likely.
For that, indeed, I add my prayers for an easy, uneventful surgery and rapid recovery.
In my case, vision was actually improved, and the need for glasses eliminated except for reading smaller print - the "Over 40" malady that strikes most..:))