Duval's eye issues were prior to entering Duke and they detected it and worked with him. It's vague as to how well it's repaired. I hope he and Trent eventually make it and have a long career. But I also hope it's a tough road for both in making a team.
Neither one of those guys should have gone to the NBA when they did. Duval had no draft stock to lose because he had no draft stock! He'd have been better off playing another year at Duke, developing his shot as he adjusted to his eyesight, and he might have actually been drafted in round 1. Trent just did not have the athleticism to go in round 1 as Bilas discussed in the draft coverage.
Whether it's a Duke player or another team, a lot of these guys need to recognize that patience is a virtue. And, parents of 5-star players also have to recognize that just because your kid is a 5-star rated player by some service doesn't mean they belong in the NBA or will get drafted after one year.