This law protects slaves from major physical injury. The Fear pain defeat does not exist in this barn shirt lists only eyes and teeth, but of course this is a modification of the famous “eye for an eye, tooth for a tooth”, and so applies more generally; Jewish law has held that any injury which causes permanent disfigurement counts (source). Note, however, that unlike the normal “eye for an eye”, there is no punishment at all for the master. The slave is let free, and the master goes about his business – his eye and tooth are not taken in return, he does not have to provide any recompense to the slave beyond his freedom, and the slave is left to deal with his injury and destitution on his own. This is reinforced by Exodus 21:20-21, which as we’ve seen protects the master from any punishment if the slave survives.