Why Do Shark Eyes Turn White When Attacked?

With their cryptic nature and incredible adaptations, sharks have always commanded both awe and horror in the world of marine secrets. The change in shark eyes during an attack is one such fascinating occurrence that has captivated the interest of both experts and enthusiasts. 

It is not unusual to see these powerful predators’ eyes turn a strange, ghostly white during a fierce battle. But what is causing this fascinating and contradictory response?

This article delves into the world of marine biology to investigate the evolutionary implications and potential physiological causes of this puzzling event. 

Sharks are fascinating creatures of the deep, and learning the reasons Why Do Shark Eyes Turn White When Attacked? reveals one of nature’s clever survival mechanisms in action.

Why Do Shark Eyes Turn White When Attacked?  

Marine biologists and amateurs alike have become fascinated by the unique phenomenon of shark eyes becoming white when threatened.

Multiple variables contribute to this remarkable behavior, even if the precise causes of this change in eye color are not entirely understood.

Here, we examine the potential reasons in the following ways:

Tonic Immobility

Sharks can go into a state known as tonic immobility when they are attacked or exposed to stressful circumstances.

This reflexive reaction causes a momentary condition of paralysis, making the shark appear vulnerable and immobile.

Evolutionary Defense Mechanism 

Tonic immobility and the alteration in eye color are thought to be evolutionary defense systems that have evolved over millions of years.

The shark might deter future attacks by making itself appear limp and incapable of moving, fooling its attacker into thinking it is dead or otherwise helpless.

Nictitating Membrane

Sharks have a third eyelid that serves a specific purpose called the nictitating membrane.

It protects the eye while maintaining visibility with its translucent membrane. The nictitating membrane may roll across the eye during tonic immobility, giving it a white look.

Protection for the Eyes 

During tonic immobility, the white hue of the eye may help to shield the shark’s eyes from potential damage during an attack.

The shark protects its delicate ocular tissues by covering its eyes with the nictitating membrane.

Predator Confusion

When a shark’s white eyes are visible, larger predators or prospective threats may become confused about the state of the shark.

Given that predators frequently target weak or injured prey, this misunderstanding might discourage further aggression.

Preventing Eye Injury 

To find and follow their food, sharks mostly rely on their senses, particularly vision.

They reduce the possibility of alerting attention to their visual powers by controlling their eye movement and showing white eyes, potentially preventing any further assault.

Stress Response

In sharks, stress responses may be associated with tonic immobility and changes in eye color.

When an animal perceives a threat, its physiological condition shifts, causing changed blood flow and pupil dilation, which may result in eye whitening.

Variability among Species

Not all shark species exhibit this shift in eye color during tonic immobility. Depending on the species, the individuals’ unique characteristics, and the particulars of the attack, the phenomenon’s frequency may vary.

Why Do Sharks Close Their Eyes When They Bite Their Prey? 

Sharks have a distinctive behavior where they close their eyes when biting their prey. While this phenomenon may vary depending on the species and the individual, several elements play a role in this unique behavior.

The main justifications for why sharks close their eyes while biting their prey are listed below:

Protection of Sensitive Eyes

Sharks have highly developed eyes, yet they are prone to damage when they engage in aggressive interactions with prey.

Just before biting, they close their eyes to shield their vision from any potential damage brought on by the thrashing and struggling of their prey.

Nictitating Membrane

The nictitating membrane, which is a translucent third eyelid present in some species of sharks, is a specialized feature unique to them.

To further protect their delicate eyes during strenuous activity like feeding or attacking prey, this membrane serves as a protective shield, covering the eyes.

Increasing Sensory Perception

Sharks possess a remarkable variety of sensory organs, such as the Lorenzini ampullae, which can detect faint electric fields produced by possible prey.

Sharks may concentrate more on their other sensory clues, such as vibrations and motions in the water, by closing their eyes during an attack to more precisely target their prey.

Lateral Line System

Sharks’ lateral line system enables them to sense water vibrations and motions, which helps them find prey even in dimly lit areas.

During an attack, closing their eyes may help them focus and lessen sensory overload so they can make efficient use of this important sensory system.

Energy Conservation

Sharks are energy-efficient predators that seek to increase their odds of successful predation while minimizing their energy use.

They can retain overall endurance throughout prolonged hunting expeditions or when pursuing prey that is moving quickly by closing their eyes during an attack.

Reducing the risk of eye injury

During a feeding experience, sharks may come into contact with sharp or possibly dangerous things from their food, such as spines, bones, or teeth.

By closing their eyes, they lessen the possibility of suffering eye wounds that would make it difficult for them to properly hunt.

Maintaining Focus

Sharks may be able to maintain their focus by closing their eyes as they capture and subdue their prey.

They may completely utilize their other senses and increase their efficiency as predators by removing visual distractions.

Stealth and Surprise 

Sharks are sneaky hunters who depend on surprise to take down their prey. Closing their eyes as they come closer to their target may help them avoid detection until the very last second, increasing the likelihood that their ambush will be effective.

Species Variation

It’s important to determine that different species of shark act differently. The hunting methods and sensory adaptations of various species may vary, which may have an impact on whether they close their eyes during an attack.

Can Great White Sharks Roll Back their eyes?

No, unlike some other shark species, Great White Sharks cannot roll their eyes back into their heads. Sharks with a particular third eyelid called the nictitating membrane, which can cover their eyes for protection, can roll their eyes back. 

Some shark species may shield their eyes during feeding, mating, or other potentially dangerous activities because of this membrane.

Great White Sharks don’t have a nictitating membrane, though. Instead, the scleral ring a robust, cartilaginous structure that helps preserve the shape and integrity of the eye protects the eyes of these animals. 

Although it offers some eye protection, this structure does not allow for the same range of eye motions or completely enclose the eyes as does the nictitating membrane in other shark species.

Because of this, great white sharks cannot roll their eyes back into their heads. Similar to how human eyes are fixed in place, their eyes remain in a fixed position within their eye sockets.


What color eyes do great whites have?

Eye color on Great White Sharks typically ranges from deep brown to nearly black. While hunting in the open ocean, this color acts as a natural sunblock, shielding their eyes from harsh sunlight and glare.

Dark pigmentation is a characteristic shared by many predatory marine species and aids in maintaining the integrity of their delicate ocular structures.

Do sharks go blind when they attack?

Shark attacks do not cause them to go blind. Rapid eye movements and probable water debris during violent interactions may briefly impair their vision, but they quickly regain it.

For the most part, sharks rely on other senses like electroreception and scent to successfully locate and capture prey.

What color eyes do great whites have? 

The eye color of Great White Sharks normally ranges from deep brown to nearly black.

While hunting in the open ocean, its black coloration helps shield their delicate ocular tissues from harsh sunlight and glare.

Why do sharks roll their eyes back? 

The nictitating membrane is a unique membrane that some shark species, like the whitetip reef shark, have that covers and protects their eyes during hunting or when handling prey.

The nictitating membrane rolls back over the eye as they bite, adding a line of protection and preventing eye damage.

Why are white sharks’ eyes black?

Due to their dark pigmentation, Great White Sharks have black eyes, which help shield their delicate ocular tissues from intense sunlight and glare when they forage in the open ocean.

Their black coloring acts as a natural sunscreen, keeping their eyes clear and effective for their life of predation.

Scientists and aficionados have been enthralled by the mysterious world of sharks for years, and their distinctive behaviors continue to reveal astounding adaptations.

Researchers have been confused by a fascinating phenomenon: when threatened, sharks’ eyes turn a ghostly white color. 

This remarkable response, referred to as “tonic immobility,” raises concerns regarding its underlying relevance and evolutionary purpose. In this study, we explore the processes underlying Why Do Shark Eyes Turn White When Attacked?

As well as the evolutionary tactics and anatomical traits that enable this mesmerizing display. Understanding this fascinating behavior helps us better understand the remarkable tenacity and survival tactics of these extinct marine predators.