Rose
You could be having an allergic reaction to some food or other. I have had a sharp pain in one or both eyes after overindulging in a food like peanuts. A spacey feeling such as you describe is also a common symptom of a food allergy. I suggest you do some research in that area and also take note of what you may have eaten in the hours before an episode of opthalmic migraine. Remember, there is a cause for every effect!