Teary-eyed when I yawn (question about eyes/eyesight/sleep)?

Whenever I yawn, my tear ducts produce tears. Whenever I get caught facing the opposite direction of the wind (looking "into" it), I get teary-eyed and it gets hard to see. Same thing with excessive amounts of chlorine in pools, unless that's just a sensitivity to chlorine. What seems to be the problem? I've seen an answer that relates to a lack of sleep, but on the weekends I'll sleep for 12 hours straight (which I have now come to hate) and on weekdays I'll average 6-8 hours. Eye doctor visit? I always seem to yawn and be tired, but I can't explain why...