Brief Answer: This can be prodromal symptom of migraine. Detailed Answer: Hello Welcome to Health care magic Iam Dr.Dadapeer K, an ophthalmologist and I answer health problems related to eye. It seems from history that you are having flashes of light in the right side of vision. The commonnest causes for flashes of light is as prodromal symptom of Migraine. Here the flashes of light are usually followed by headache or light headedness and this comes in once in a week or a month depending on the frequency of the attack. Investigations like MRI will be normal in cases of primary headaches and they require treatment by a physician. If the attacks are very frequent prophylactic drugs like propranolol can be used to prevent attacks of migraine. The other less common cause for flashes of light are brain lesions involving the occiptal lobe. Since you have undergone MRI and it is normal these problems are very much unlikely. As an Ophthalmolgist I would like to rule out eye causes for Flashes of light. Sudden onset of Flashes of light are usually seen in retinal problems like retinal tear, retinitis, vitreous detachment....However since flashes of light are present since long time and they are not associated with floaters the eye causes in your case are very unlikely. Hence I consider Migraine as the most probable cause in your case based on the symptoms and investigation reports. Hence I advice you to consult your physician for further evaluation and treatment accordingly. Hope i have answered your query and the information is helpful to you. Thank you

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