This looks really very good! Nice work with minor changes needed.
Your handout is great. If it is a download, then you need to confirm that it is copyright free and provide a link back to the source directly from the handout page (not from your main wiki). If it is your own work, then you need a statement confirming that.
You need to provide a printable blind spot tester. If the one you used has copyright issues, then make one that approximates the dimensions used.
If this statement is true: not all human beings have a blind spot then you need a citation. I'm not aware of this, but I have not done the research that you guys have done. It is important that the resource be truthful in all aspects. As I understand it, all vertebrates have blind spots. Please correct me if I am wrong and provide a citation.
I don't see a math connection here. There are no mathematical concepts articulated. Why not replace this section with an artistic connection that would be easier to justify. None of the data gathered are numerical, so I'[m struggling to see the math.
Please find some more resources here. There are several child-friendly anatomy books including coloring books. I like Magic anatomy (please keep it in), but it's currently hard to find.