Iran’s supreme court ruled last week that a woman who blinded another in an acid attack would receive a literal eye-for-an-eye punishment for the crime. Two years earlier, the unnamed woman had thrown acid in the face of young woman named Sima in the city of Dehdasht, roughly 500 miles south of Tehran. The attack left her victim blind. Now, under the Sharia legal principle of qisas (retaliation in kind), the condemned will receive the same treatment as her victim. The head of provincial judiciary, Majid Karami, was quoted by the Tasnim News Agency as saying: “The sentence to blindness in one eye, payment of blood money (compensation), and seven years imprisonment have been confirmed by the highest court.”

The actual implementation of this punishment in countries where Sharia law is the law of the land is relatively rare. Victims and the families of victims have the power to commute the sentences, and often they accept compensation (colloquially known as "blood money") in the place of corporal or capital punishment. In this case it seems that the victim and her family may have settled for partial retribution, as the accused woman was sentenced to lose vision in "only" one eye.

Public commentators on the incident have condemned the punishment, describing the practice as "medieval." What critics often forget, however, is how many religious leaders throughout history have endorsed blinding as a form punishment — and for how long these punishments have been carried out.

At one time or another, nearly every society has practiced capital punishment. Execution for murder has most commonly been justified on the grounds that people who take life deserve to lose their own. But when it comes to lesser crimes, the idea of losing a bodily member, including one’s eyes, gets more complicated.

The most famous example, from which the expression “eye-for-an-eye” comes, is found in the ancient Israelite laws encoded in the Bible. Even the least attentive Sunday school student is familiar with the saying “an eye for an eye, a tooth for a tooth” (Exod. 21:23-25; Lev. 24:20; Deut. 19:21). But the earliest example of bodily mutilation as punishment comes from the Code of Hammurabi, the Babylonian law code of ancient Mesopotamia that dates back to the 18th century BCE. Among many other prescriptions, the code stipulates that hand amputation should be performed with a bronze knife if a son strikes his father or if a physician performs either an operation that results in the death of the patient or an eye surgery that destroys the eye.

For the ancient Romans, the principle of lex talionis — the law of retaliation — was foundational to the Roman understanding of crime and commensurate punishment. Under this philosophy, for example, arsonists in ancient Rome were frequently burned alive. Monetary compensation was also an option: the Twelve Tables of Roman Law mentions that "if anyone has broken another's limb there shall be retaliation in kind unless he compounds for compensation with him."

The Romans do appear to have had a particular fascination with the removal of eyes. In an article on dismemberment, renowned classicist Glenn Most has shown that gouging seems to have been a feature peculiar to the Roman period, or at least of literature produced in the Roman period. In one story from the historian Suetonius’ Lives of the Twelve Caesars, Octavius, better known as the Emperor Augustus, gouges out the eyes of a would-be assassin. In another, Nero uses gouging to manufacture deformity in the world around him, and in another a contrite Hadrian attempts to compensate a slave after removing his eye with a writing implement for a minor offense. These examples, however, were fairly ad hoc and do not appear to have made their way into official legal codes.

You might think that this kind of brutal retributive justice ended with the rise of Christianity. After all, Christians are taught that Jesus was more focused on forgiveness than punishment. But while the New Testament quotes Jesus as saying that one should turn the other cheek instead of demand an eye for an eye, there are other passages in which he seems to instruct people to self-amputate. In Mark 9, Jesus actually instructs people that if their eye causes them to sin they should pluck it out, for because it is better to go into the Kingdom of Heaven one-eyed than to be thrown into hell. Modern scholarly readers tend to assume that this parable is a metaphor designed to show just how disastrous sin is for the fate of the person after death. Maybe it was, but this was not the position of a succession of Roman emperors influenced by a more literal interpretation of Jesus' teachings.

The emperor Constantine, for example, ordered that runaway slaves be punished by the amputation of a foot, and on one occasion instructed that the tongue of an informant by torn out. And by the sixth century CE, mutilation became quite common in Christian contexts as a form of punishment. Emperor Justinian’s legislation stated that heretical scribes and fraudulent tax collectors be punished by having their hands amputated.

Notably, the use of mutilation as a form of punishment was unknown in Roman law prior to the advent of Christianity, and the justification for these punishments was explicitly grounded in the Gospel. Several hundred years later, in the medieval period, the Normans introduced blinding as a common punishment for thieves. Blinding as punishment had consequence of staining blindness with a criminal dye. Edward Wheatley’s Stumbling Blocks before the Blind reveals that those with a visual impairment — the majority of whom were, of course, not criminals — were frequently socially stigmatized as a result of their potential criminality.

Even as lex talionis gradually died out in Christian societies over the course of the medieval period, it continued to exert influence into the early modern period and beyond. While they rejected the idea that it should be enforced, Reformation thinkers like Martin Luther and John Calvin pointed to this principle as evidence for the importance of using natural law for the government of society. And in a 2008 article for Liberty University Law Review, David VanDrunen argued that “even where the lex talionis is not literally carried out, the theoretical threat of the lex talionis can provide a helpful and perhaps even necessary means of justice.”

Financial reparations, perhaps the latter-day equivalent of lex talionis, create their own set of problems — namely, by perpetuating inequality. While we can agree that the shift to financial compensation is preferable to legally sanctioned maimings, it can cosset the wealthy from facing the consequences of their actions. The guiding principle of an “eye for an eye” was equality: your eye is as valuable as mine. But when bodily punishment was commuted to reparations, the wealthy found themselves in a stronger position. The rich were more able to pay off victims than the poor, and so the poor were more likely to receive the most brutal of punishments.

The principle extends beyond the criminal justice system. Modern insurance policies continue to view our bodies in terms of the valuation of individual functions and parts. Justin Foa, CEO and President of Foa and Son Insurance brokers, told The Daily Beast that most state worker’s compensation systems have codified the worth of body parts and developed elaborate criteria for identifying how much function was lost. Accidental Death and Dismemberment policies stipulate how much your arm is worth should you lose it.

But whereas in the past one human being’s eye was viewed (in principle) as equally valuable to another person’s, today the value of human body parts is often correlated to their earnings. It’s why athletes and rockstars and Mary Hart can pay to have their body parts valued for massive amounts based on the less–than egalitarian principle that their body parts are essential to their earnings and are therefore worth more. In insurance, Foa added, the principle of an-eye-for-the-financial-value-of-an-eye constantly applies. This seems quite natural to us.

In the meantime, however, the bigger issue of state-sponsored blinding remains. Authorities claim that they are enforcing the law in the Dehdasht case in part because of a recent rise in acid attacks in the region. They hope it will act as a deterrent. The net result, however, is more violence. Which has to make you wonder: if we enshrine violence in our legal system, can we ever hope to eliminate it from our society?