Strange Phenomenon

I am a single eyelid person and I discovered my single eyelid has transformed to double eyelid after my trip to US.

look closely to the left

But this transformation only applies to the left eye. My right eye has half of the "double eyelid" only. I don't know what to make up of this sudden transformation. My colleagues joked my skin had wrinkled too much over there to cause this phenomenon. But I guess this is what you would a good problem!