OK, for the record I LOVE tinted eyes in a mascot! I've been obsessed with this aspect of mascot construction since early on. When you look at Mickey and Minnie Mouse don't you just love those nice shiny plastic eyes? Ok, maybe you don't notice that - but I do!
When I first started making mascots at the tender age of 13, I - ingeniously or naively - would take large plastic soda bottles and cut out the center part so I had a nice clear and flexible piece of plastic to use. Then I would use peel and stick car tint, cut the pupil shape out and apply it to the clear plastic and paint the edges white to make eyes. Looking back on it, they weren't half bad and hey, it was probably the first reuse of plastic bottles before it became trendy!
Making tinted eyes for a mascot is absolutely the best way to give the mascot a life-like character - a "soul". It's common for people to be confused and ask "where does the person see out of ?" since they tend to look for a screened mesh area. Its also much easier for the performer to see out of tinted eyes since it's just like looking through of a pair of sunglasses.
The only drawback you might encounter (and depending on the weather conditions) is that the eyes will want to fog up. To avoid this you have to make sure the head is vented properly to allow airflow in an alternate area (ear holes, large mouth opening, etc.). A fan is almost always necessary to avoid fogging up with this type of eye installation. You can also make the eyes in such a way that the pupil is recessed back from the outer white eye area just a bit to allow a small gap for airflow around the pupil however, this is a more advance building technique and can be challenging for the beginner masot maker.
I've moved on from soda pop bottles and am now making tinted eyes using custom vac form molds for a professional look and quality. It's always good though to look back at your roots for inspiration and see what you can improve on with your current techniques. If your interested in trying your hand at making tinted eyes, search your grocery store or other local shops for things like the bottoms of clear plastic soap bottles and different condiment containers. Food and housewares stores are great places to find things that are already shaped properly for eyes. Keeping my creativity on alert and trying to see the potential in everyday household items is my most favorite part of doing this kind of work! Let me know how your creativity and ingenuity works for you!