The Reality of Laser Vision

For superheroes (and villains), it seems like the ultimate sign of power is laser vision. The ability to focus and shoot a beam of intense destruction directly at an opponent is an effective way to deter any other super-powered individuals. When eyes start to glow, others in the vicinity know it’s time to swiftly vacate the area. Although this ability only exists in fiction, it’s an interesting ophthalmological exercise. How would it work in the real world – and what damage would it cause to its surroundings… and its user?

The informed among you may point out that not all eye beams are created equal, and some – for instance, Superman’s heat beams – are not even lasers at all. But it’s lasers that have taken center stage in the world of eye beams. And though at first thought the idea seems ridiculous, laser vision may not be as farfetched as you might initially think.

For the most part, lasers have relied on artificial or engineered optical gain media from which electrons can be excited to release photons. However, researchers in a 2011 study were able to generate biological cell lasers using fluorescent proteins as the gain medium, with cells able to emit hundreds of laser pulses before they expired (1). Although that doesn’t mean that we’ll be shooting lasers from our eyes tomorrow, hypothetically speaking, if an individual had a mutation that modified their rhodopsin gene (2) to encode enhanced fluorescent protein fusion and a way to excite the electrons within the proteins and focus the photons released into a coherent beam, laser vision could be plausible.

So what kind of damage could such eyes do? The damage a laser does depends on its wavelength and power; the most dangerous lasers are those that are both powerful and capable of emitting light of shorter wavelengths. Blue lasers, which release photons with the highest energy, have the potential to do the most damage, with even consumer-grade blue laser devices able to set plastic or paper on fire from a short distance. Lasers’ effect on the human body can also be devastating, causing damage to eye and skin tissues through multiple mechanisms, including thermal burns, photochemical damage, and photoionization. The eye is particularly vulnerable to injury because it is designed to take light entering through the pupil and focus it onto the retina – but doing so with high-powered laser light can cause irreversible damage. This, ironically, is likely what would happen if two superheroes used lasers on each other’s eyes at the same time; both beams would likely pass through each other to reach their targets, rendering both participants blind. (And a new origin story begins…)

From this, we can probably conclude two things. First, the fact that Superman’s eye beams are red may actually be, in an odd way, a strange mercy to his foes. And second, that laser eyes, although an enhancement to a hero’s arsenal on the big screen, would likely be terrible in practice.

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