Dermatologist I am an 80 year old lady who has sleep apnea. I noticed a small light brown spot near the outer aspect of my left eye, on the cheek bone, about 1 1/2 yrs. ago after using a nasal mask for approx. 3 yrs. I switched to using nasal pillows but the straps travel across this area and this is now a 17mm x 20mm darker beige mark. It does not appear to be raised or have depth, and feels like regular surrounding skin. What causes this mark? Anything to be worried about? Simonne