Shrek (the sheep) and sheep wool

Excerpts from an article at Modern Farmer:

[For] six years, this New Zealand [sheep] managed to avoid spring shearings by hiding in a cave. By the time he was found in 2004, his owners couldn’t even tell he was a sheep... When Shrek was eventually sheared.. there was enough wool to produce 20 men’s suits....

Which led us to some basic questions:...We turned to Dave Thomas, head of sheep studies at the University of Wisconsin, Madison....

Modern Farmer: Let’s get right down to business. Will wool just keep growing and growing if humans don’t cut it off? 

Dave Thomas: For domestic sheep like the Merino [Shrek's breed], the answer is yes.

MF: So domestic sheep have evolved based on the way we groom them?

DT: That’s right. Primitive sheep like Bighorns in the West still shed most of their wool every year. And domestic sheep, the ones raised primarily for their meat, will do some shedding. But for the majority of sheep, there is continual, year-round wool growth...

MF: Are there potential health issues?  

DT: Full fleece can be bad in very hot weather, sometimes leading to heat stress. There are also mobility issues: if a sheep with long wool lies down on a heavy incline, it can be impossible for them to roll off of their backs. In extreme cases, they can die.

MF: ...What about vision? It looked like Shrek would have a hard time seeing through that mess.

DT: That is what you would call “wool-blind,” when the sheep’s vision is actually impaired. 

Photo (adjusted for temperature and tint) from Modern Farmer, where there are additional photos of Shrek being sheared and his post-shearing status.