What about putting an Arduino ultrasound module??

[Annies]

What about putting an Arduino ultrasound module for misuring the depth of what the laser is pointing at and then a variable focal point lens so that the laser is more in focus?

 

[ZandraJoi]

What about putting an Arduino ultrasound module for misuring the depth of what the laser is pointing at and then a variable focal point lens so that the laser is more in focus?

I'm not familiar with this. What would be the advantages & disadvantages? Have you tried to use this? What did you think of it?