Diagnosis. I have:
Fifth disease, a viral infection "commonest amongst 4 - 10 yr olds."
Conjunctivitis, possibly viral, possibly bacterial
The irony of my having contracted (commonly) childhood diseases is not lost on me. Nothing serious, and stuff you'd see in a third-grader. (Insert obvious remarks about maturity here.) Although as resonance42 gently suggested, I should not have toughed it out for nearly a month before going to have it looked at.
Anyway, must go as I'm late for a dinner; thanks again for listening!