Can I pursue legal action against an employer for knowingly increasing surgery pain by forcing me to work overtime?

After PRK surgery my employer not only ignored my request for leave but gave me additional overtime tasks after I indicated that I was in pain. Even after I specifically informed them of my condition it took a contract project manager to get them to let up. Since the assignments were directly from the CTO I didn't feel I could refuse them without losing my job. I worked an entire day in front of the computer with one eye taped closed and was miserable for two weeks as a result.