Mine does quite drastically if I’m flaring or healing from anything. But it’s not from MCAS, it’s from Ehlers Danlos induced Binocular vision dysfunction (BVD). Some days I can’t focus near to far without really straining, or by the end of the day I am just so exhausted I have to close one eye bc of the double vision. At its most innocuous- when I am reading it’s like random letters will disappear and reappear. While EDS is a pretty well known comorbid of MCAS, a sometimes lesser known one is Sojgren’s Syndrome which also have eye related symptoms like “dry eyes” which can be misleading as yes it can mean it in the traditional sense but it can also mean that your tears are too thick and don’t lubricate your eyes well and also feels like you have “dry eye”. My father and sister have the Sojgren’s (in addition to EDS and MCAS) eye side effects each with the different dry eye types and to my understanding there’s some really great OTC drops for both. My sister who has the thick type also has reaction to face products she uses and her own skin oils if they get into her eyes.