The idea of going blind.
And also; heights, airplanes, crowds, enclosed spaces, heights, insects of all kinds (ever seen a close-up of a butterfly? Those things aren't beautiful, they are fucking monsters), spiders of all shapes and sizes, large machines, heights, elevators, disease, dogs (to a degree), birds and their evil eyes staring at me, plotting my doom, heights, the idea of the ceiling collapsing over me when I'm asleep, most types of vehicles because I don't like the thought of how many people die in car crashes and the likes every year, heights...
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I may or may not have issues.