Honestly going blind is a fear for me for everything (never seeing my family or my SO smile again, or the rain, etc.) except programming. It would be hard but things like Emacspeak really make me feel like someone's taking care of the hypothetical vision-impaired me that could happen. It wouldn't be peachy but I wouldn't feel suddenly lost either.
My biggest fear for my job is injuring my hands irreparably as they are really my bread and butter as a programmer. I invest heavily in quality keyboards and personal tracking software (mostly self-written) to keep tabs on not going overboard and triggering the onset of RSI or other health issues related to the hand and wrist.