I have been prescribed glasses for about four years now, they are for long distance viewing. I do not wear my glasses full time, only when I need to. For the past three years I have been getting random outbursts of blurry vision, sometimes in one eye and sometimes in both, this will happen at least once a month and will last about half an hour. It's like ripples in my eyes and I am unable to see clearly, it is very scary because if I was walking or driving I would not be able to see where I was going. I also suffer from migraines and these have become frequent in the past year. I was wondering whether the blurry vision is a result of me not wearing the glasses often or if it is something I should consult my doctor about because I am aware that frequent headaches and blurry vision can be a result of a brain tumor.
The problem you describe will not be the result of not wearing your glasses. You symptoms are indicative of the visual aura associated with migraine, and indeed you do say that you suffer from migraine, but you have not related the symptoms. This may be because the type of migraine has changed and you have not experienced this type of visual symptoms in the past. Typically the visual symptoms tend to be in both eyes, not always at the same time, and tend to 'fade' away rather than clear up suddenly. Your symptoms are not indicative of a brain lesion which are very rare. Nevertheless it would be a good idea to have an up to date eye test where your optometrist will check your vision, prescription and the health of your eyes. Then I would see your GP to confirm the diagnosis and see what he or she recommends.