You should see an optomostrist. Twitching is normal though its a sign of stress, but blurred and double vision could be a sin that you need glasses or a stronger perscription. please answer mine.
could be certain type of worms but it will need a test (stool sample)
another propability if you felt a naggin feeling at the vision center of your brain that could recquires a consult
or you are on some herbs such as santonica,it causes blurry visions
You need to see an opthamologist. There is a eye doctor on medhelp. Go to the forums and look under E and find the eye care or eye section. I hope they can advice.