I think they give u a misleading thing :D
I mean they are correct but these answers can mislead u :D
in fact 我能看到你 and 我看得到你 are the same.
for example, if I am behind a door, u can say 我看不到你 or 我不能看到你 to me. one more time, they are the SAME.
their difference is: 我能看到你 highlights the ability which is "I CAN see you" and 我看得到你 highlights the result which is "what do I get by using my eyes?--------ah, I see you"
as u know, 得 is used for an adv who follows a verb, such as 跑得快 做得好 etc
here 看得到你 看 is a verb. 到 is an adj (till/untill). 你 is a noun. adj + noun = adv
my sight doesn't stop until you. so this highlights the result of seeing.