Weather
Indoor or outdoor lighting issues I have needed a lot of light for quite some time now. I have attributed it to advancing age and not to SOM, but who knows?
Strobing This bothers me. Like in the car, or biking in the woods with the sunlight peaking through the trees.
Night driving I have always had problems with seeing in the dark when driving. Incidentally, I also have always had to wear sunglasses while driving (unless it's dark or very cloudy), so I have a sensitivity to too much light as well, at least when driving.
Seasonal changes
Sinus and/or upper respiratory conditions
Colds, flu
Insufficient sleep I feel the eye problems are more pronounced when I don't get adequate sleep.
Emotional conditions or situations Same answer as stress, it causes more TMJ which I think causes more SOM.
Work issues, like computers or other focused tasks/jobs I have one of the most eye tasking jobs you can have, I am a contracts compliance auditor. I look at (oftentimes) really bad or small copies of timesheets and expense receipts, key this data into the computer and comparing what the contract says they could charge against what they actually charged. I am on the computer pretty much for 9 hours consecutively during the day. I do feel that this causes eye strain which exasporates the SOM.
Chemical agents, i.e. cleaning products
Stress See above.
Any other environmental or situational issues