If cobra venom comes into contact with the eyes, it can cause severe pain and even lead to permanent blindness.
Some species of cobras possess the ability to spray venom from their fangs into the eyes of their victims from a distance of over 1.5 meters, achieving an accuracy of approximately 90% even while moving.
They can predict the target’s position in a time frame as short as half the blink of an eye.
Accurate Venom Spraying Capabilities While Moving
Some species of cobras can accurately spray venom into the eyes of their victims from a distance of 1.5 meters. (Photo: Shutterstock).
To analyze the lethal spraying ability of cobras, functional morphologist Bruce Young from the University of Massachusetts (USA) positioned himself behind a sheet of acrylic and recorded the venom spraying process of the South African cobra as they targeted his eyes.
This expert found that the snakes tend to wiggle their heads before spraying venom.
Not only Young, but reptile researcher Guido Westhoff from the University of Bonn (Germany) also observed this phenomenon in cobras.
During their collaboration, Young was responsible for stimulating the snakes to spray venom, while Westhoff recorded the head movements of the snakes. Other researchers focused on filming the movements of the cobras.
They discovered that this species can achieve up to 500 movements per second, approximately 20 times faster than the average camera speed.
Over six weeks, the researchers documented 100 instances of venom spraying by the snakes. Upon analysis, they found that cobras could detect the movements of their opponents 0.2 seconds in advance, which is half the time of a blink.
In that instant, the snake could orient the direction of the venom spray to accurately target the victim’s eyes.
“Just a small droplet of pure or diluted cobra venom splashed into the eye will immediately paralyze the cornea, and the victim will no longer be able to see afterwards,” Young told Live Science.
Additionally, according to Young, the ability to spray venom accurately while moving is a characteristic that is not commonly found among snakes or reptiles in general.
After exposure to snake venom, the victim’s eye (left) will gradually become cloudy and lose its ability to see. (Photo: Healio).
The Uniqueness of the Sprayed Venom
Scientists from Liverpool School of Tropical Medicine (UK) analyzed the venom from 17 species of spraying and non-spraying snakes to identify differences between them.
According to their findings, the most common compounds in cobra venom are referred to as “three-finger toxins.” These toxins account for 60% of the overall snake venom.
However, sprayed cobra venom contains a higher concentration of phospholipase A2 toxins, which are found in minimal or nearly absent amounts in the venom of non-spraying snakes.
Through experiments on mice, researchers found that “three-finger toxins” combined with phospholipase A2 can cause significantly more intense pain.
Specifically, sprayed cobra venom can stimulate mouse nerve cells twice as much compared to non-sprayed venom.
In an article published in Science, biologist Nicholas Casewell noted that the venom of some snake species has evolved to enhance their defensive capabilities.
In agreement, toxin researcher Stephen Mackessy from the University of Northern Colorado (USA) stated that the evolution of venom in snakes to cause blindness is a way for these creatures to ward off other predators.
However, the exact reason why snakes evolved to spray venom remains unclear.
Some researchers suggest that this adaptation helps snakes protect themselves from being stepped on by large mammals, despite the fact that the eyes of these animals may find it difficult to be targeted by venom sprays.
According to Casewell, prehistoric humans posed a threat to snakes, which could be a reason for their evolution to spray venom.
“Our ancestors were a threat to snakes. Humans have forward-facing eyes that are unprotected. This could be a good target for snakes to evolve to spray venom at humans,” he analyzed.
