Hello, Dr. Choudhary! Thank you for being so kind as to make yourself available online to answer people s health-related concerns. I m wondering if you can tell me what might be the possible cause of my getting a large, partially-obstructive spot in front of my eyes when I have been exherting myself, lately (for example: shoveling snow, or when making repeated trips up and down the stairs to bring in the groceries from the car). I am a relatively fit, middle-aged female. 5 ft. tall and weigh 101 lbs. I avoid sugar, processed and fatty foods as much as possible, never smoke/d, seldom drink alcohol, and never drink coffee. Also, moderately exercise (mostly just walking, stair-climbing, and stretching 2-4x per wk, though), and my BP, BMI, HDL & LDL levels are all good. The spot is large (obstructing roughly about 1/4 of my vision field, seemingly about 11:00 on my right side, but seen with both eyes); is always somewhat heart-shaped, but a bit flattened; and at first is black at the bottom and brilliantly white on top (like a bright, white light), that continues to brighten and even pulsate if I continue to exhert myself. Of course I stop! And then it slowly fades. As it fades, the bottom becomes gray and eventually grows upward into the white portion, causing the light effect to diminish until the whole spot is completely gray with a spot of black in the center, and just a sliver of white (light) at the center on top. And within maybe 5 to 10 mins of resting, it s gone. Any ideas? This is one of those things that make one stop and think, Ut-oh! What the heck is this, now?