I think that irrespective of how much glasses might be intended to deflect the wind, there is always some going to get underneath. Inevitably, out of the roads, there is going to be dust in the air, stirred up likely to passing traffic, and that will i irritate the eyes.
I think also you might need to be careful that your glasses aren't actually causing the wind to draw out the air around your eye, like a venturi. This likely will cause dehydration of the eye.
Eyedrops as suggested are a good option, if you can stand them going in.
Another point might be to consider your rehydration. Bloodshot eyes are not uncommon on long-distance rides, but they may be more prevalent if you are not maintaining a high level of rehydration. Of course, it is recognised that many cyclists are in hydration deficit at the end of long rides, and this may be one symptom.
Like most things randonneuring, it becomes a process of elimination.