I don't have the best of sight, but I'm not impaired at short range. And visuospatial impairness has nothing to do with a lack of clarity. It would mean I'd have a hard time keeping track of her orbs no matter the skin used. But so far, the only times I've had troubles with that were in the middle of teamfights (when people are often standing on the orbs, obstructing vision), and were with this particular skin.
I've seen even Cait's traps under my botlane outer turret. I've seen them in bushes. But the only way I could know where her orbs were is if I saw the cast animation, or if I took a couple seconds to focus only on finding the orbs.
This was playing as Karthus that this happened, I believe. I do fairly well on him, even though I run a rather off-meta build (Seraph's+RoA, one of the strongest builds, but out of favor).
But I just couldn't see the orbs well enough to evade her E. Especially in late-game.
My "preference" for tanks has less to do with me being good/bad at them, but because, if I don't take one, nobody seems to take one at this tier. I actually main Ahri (who is fairly forgiving, but still is very susceptible to CC), but I've been stuck in top as tanks for ages. I don't have a preference for tanks (although being virtually indestructible is a very nice feeling), I have a preference for not losing to a single Fizz/Talon/Zed.