<s>[INST] I have had 2 meningioma s. The first, a frontopariatal meningioma the size of a lemon removed in 1997. The second, a parasagittal meningioma the size of a quarter removed March 2012. After having trouble with my eyesight, seizures and even just losing my complete sight for short ( seconds to minutes). I requested an MRI. it was found that I have gliosis on my left temporal lobe that has now doubled in size from 1-2 mm to 4mm. I look up gliosis but don t fully understand it and what this can mean for overall neurological well being. is gliosis dangerous? and can it be causing the symptoms I am having? [/INST] Gloss is similar to scar which persist at other part of body after injury. Gliosis if present in brain cortex or near to cortex can cause seizure. And if its affecting visual pathway (optic nerve/ optic radiation/occipital lobe), it can cause visual field defect. But not cause refractive error. If you have seizures-you need to be on antiepileptics you have never seizures-no need to take prophylactic antiepileptics eyesight I suggest you consult ophthalmologist- get refraction done and if refraction is normal get visual field charting done. </s>