"An eye for an eye" doesn't work in practice because the punishment is not harsh enough to deter the crime in the first place, at least in terms of petty crimes. If the punishment for stealing $50 from someone is that I have to pay $50, I'm gonna be stealing all day long if I believe I have a better than 50% chance of not getting caught.

For more serious crimes, like DUI, the punishments are not severe enough. You don't lose your license until you have multiple DUIs. Even then, you will likely continue driving illegally while intoxicated until you t-bone another car and kill the family inside. Then the court/jury will "struggle" to determine if you deserve the death penalty.

In fact, the harshness of punishment in general is not an effective deterrent, as illustrated by the death penalty. If you're serious about actually lowering crime rates, look elsewhere.

Actually I believe prison should be the option of last resort as nobody benefits from locking someone up where they can't work or benefit society. I would prefer compensation in the form of money or labor if possible. If not, then that individual should be sent to prison.