Without being too specific you're almost certainly straining your left side to find your own personal horizon between your ears. I won't say anymore on that - Scrap's a pioneer on the subject.

One thing you could work on is proprioception which involves balancing on wobbly surfaces i.e. a fit ball or doing simple tasks like standing on the balls of your feet/standing on one leg with both eyes closed. Also, really stretch the quads properly and for long enough to influence the muscle fascia.