Mail-Order Eyes: Horror

It itched and wiggled behind his eye, until he couldn't help picking up the pen from his desk and really working it around back behind his eyeball. It felt heavenly, just like the commercials had always promised it would. He heard a gasp and saw Sandra standing in the door to his cubicle. Papers fell from her hands as she stared at him. "Don't worry, Sandra," he assured her, "it's ok. Really. I got one of those mail-order eyes from the TV advertisement." He chuckled. "Can't believe I thought that they were scams for so long. They were right. Goodbye forever, dry eyes!" Sandra pointed and tried to say something, gagging, but only strange grunting noises came out. She turned and vomited over the cubicle wall. "What the fuck!" he heard. He couldn't help chuckling. All this fuss over a little mail-order eye.

Inspiration: Dry eyes.
Story Potential: Um. Medium. Maybe high potential to rework as-is into flash fiction. The problem is that this reeks of the amateur "and then I went cccrrrazzzzyyy!" BS that tries to pass itself off as horror fiction and fails.
Notes: I do like this little scenario, though it does feel amateurish as hell.