I thought about
Præmium videntis
but this felt laconic and uninspired. Another option that came to me was
Præmium cernentis est
which seemed more in line with the idea of seeing as understanding or beholding.
Which of these two makes more sense? How can they be improved?
Update: The sense I'm going for here is, the person who understands something, gets that thing as a reward.
I would go with a dative instead of a genitive here, but you have a couple of options, depending on what you want to get across.
The simplest is just to do a bare dative: praemium videnti, which you see in constructions like vae victis ("woe to the conquered"). This makes it feel like a pithy saying or motto, so if that's how you want to use it, feel free.
If you want to emphasize ownership, you can add esse: praemium videnti est = "there is a prize for the one who sees" or "the one who sees has the prize." However, there are plenty of times in Latin where this construction is used and I don't think it's necessarily a dative of possession. See e.g. Plautus' tibi spes est fore meliorem fortunam "there is hope for you that there will be a better fortune."
Also, instead of est, you could use datur, which would emphasize the action of bestowing the prize on the videnti.
Finally, praemium ad videntem pertinet works, yes, but this seems to imply a legal right. In the examples given in Lewis and Short at least, iure often accompanies the phrase, though not only so. Caesar is fond of the construction outside legal uses.
All mean essentially the same thing but differ only in nuance.
Note that while videre can mean "understand," it's more idiomatic in English than Latin. I'd probably recommend scire instead. See this discussion for reference.
