Are there any proven ways to slow myopic progression in children and college students?

Not really. There is not yet enough convincing evidence to support intervention to slow down the progression of myopia (near-sightedness).
Slightly. A big article came out last year which proved a slight slowing of progression in those who took Atropine drops. But the drops have side-effects, and i doubt it's worth it. But yes- there definitely was a slight slowing.
Yes Atropine drops. Atropine eyedrops have a proven record of reducing the progression of myopia. See an ophthalmologist.