The Polymorph spell functions as the Alter Self spell, except where otherwise stated. For example, with Alter Self, it specifically states you do not gain the special vision of the new form. For Polymorph, it does not specifically state that you do gain the vision of the new form. However, some types (Aberration, Animal, Giant, etc.) provide some enhanced vision, and the Polymorph spell does say that your type changes. It does not say whether or not you gain all of the abilities of the new type, and the Type description does say that not all creatures of the type have the traits stated.
But, I am confused at this point which is the specific and which is the general rule in this case. Changing type definitely changes what spells affect you, but I am not sure if it also confers vision when Alter Self specifically states it does not, and Polymorph functions as Alter Self. Would Polymorph need to explicitly state that you gain the vision of the new type when you apply the new type? Or does applying the new type automatically confer the vision of that type, as that is the specific rule and Alter Self is the general rule?
I have been ruling that Polymorph does not confer vision, even with type changes. But, as I think about it, the fact that I allow polymorph in my games is already allowing phenomenal cosmic power. Am I being pedantic by not allowing it to confer vision when the type clearly states the vision is part of the type? My players are not complaining, and I probably care more than they do. In the end, I have already made a ruling and it is working for my games, but I like closure, and I would like to know if my ruling was "best".