Can Fish See Water?

In angling and the scientific world, this is one of the most prolonged debates. It is an exciting question which points out much research by scientists. Do you think fish see water? Are they even aware it is their habitat? 

In this article, you will also discover if fish see color and how accurate their sight is. You will even understand if they have other senses and their water survival. Please stick with us to discover the fine details if fish can accurately see the water.

No, they can’t. Like how we cannot see air, fish cannot see the water. The brain tries to filter out constant vision noise like the air or vision obstacles like a nose.

The brain filters information like air, smell, body noise, and anything with related details to save the processing power to focus and survive. Fish and sea creatures evolved the same way we did on land to filter out air, smell, look, and taste. Water is a constant environmental noise, making them unable to see, taste, hear, or smell it. 

Do Fish Know They Are In The Water?

Do Fish Know They Are In The Water

Fish don’t recognize that they are in the water. It’s impossible to see because water surrounds them. They can observe how it affects other objects, but they can’t see it. They flush it through their gills to survive, feel its resistance as they swim, and see stuff floating in it. Fish have gills adapted to extract dissolved oxygen from the water for survival. 

Fish cannot drown due to submersion or inhalation of the water unless they’re removed from the waterbody. But they would suffocate due to lack of enough dissolved oxygen, which is extracted through the gills only in water. 

Do They Drink Water?

Freshwater fish do not take much water through their mouths to avoid unbalancing the saltwater balance within their bodies and over-diluting their blood. In their body tissue and blood, they have a higher salt concentration than the water in their surroundings. They allow water in small amounts into their bodies through the skin and gills via osmosis and pass out excess through urine.

Saltwater fish live in water with a higher salt concentration than the salt present within their bodies. This may seem ironic, but they are at constant risk of dehydration even though they live in water. Osmosis leads to water movement from their bodies to the water surrounding them. They actively drink water through their mouths then produce small amounts of salt and salty urine through specialized cells in their gills.

How They See In The Water:

The fish’s eye configuration is equivalent to ours, with the main difference being how we refract light. Fish eyes are better modified to see movement and contrast relative to the precise detail. They have a bug-eyed appearance from their round eyes, which allows them to refract light differently. Their vision is quite impressive in the underwater environment because they have a round lens optimal for bending light. 

Fish see better compared to an average diver in the water surroundings. Just like us, they depend on their vision to maneuver all through their daily lives. They have wildly impressive abilities to see the world around them regardless of being unable to see the water. As each day passes, their eyesight develops in better ways to help them survive. They look at something directly for it to be in clear focus like a camera. 

How Clear Can They See In The Water?

The amount of light penetrating underwater is hugely affected by water clarity. Water clarity is determined by factors such as suspended particles, the angle of the sun, algae, and wind action. Due to algae (which appears green or brown), barely any light penetrates, and water clarity may be so low in the warmer months in a shallow pond. Fish don’t see water even though they may have the capacity to see a lot in their underwater world. 

Composition Of The Eye Of The Fish:

The components of a fish’s eye work in slightly different ways considering how the light behaves, but it is similar to that of a human or any other vertebrate.

LensForms an image and focuses on objects typically in the center.
IrisWorks to adjust the levels of light in their surrounding.
CorneaIt protects the eye and allows it to collect light information from an extensive field of up to 360 degrees.
RetinaIt contains light-sensitive cells for determining light and dark and seeing color.

A fish’s retina consists of two types of cells:

1. Cones for seeing color.

2. Rods for determining light and dark.

Do Fish See Color?

Do Fish See Color

Yes, they do. All fish except rays and sharks have cones in their eyes which helps them see and distinguish colors. This means that they can see colors, including red, green, and blue, though not at night. Colour vision helps the fish see their prey against different backgrounds and identify prospective mates or predators. 

Many fish such as bass, goldfish, rainbow trout, carp, and pike can see in the ultraviolet spectrum because they have another type of cone. Some deep-sea species attract prey and find mates in total darkness through bioluminescence, where organs work with particular bacteria to produce light. 

Adaptations Of Fish To Their Environments:

Some species’ eyes are modified for diverse environments. Regardless of how developed the eyes are, a fish will see very little if there is no light reaching into the water. Other senses such as smell to detect the soluble chemicals in the water and its lateral line come in handy at such times to detect food and predators. Before migrating for spawning, some species tend to change their eyes’ anatomy. Let’s take a look at others.

Type Of Fish:Environment:Adaptation:
Whiting Deep-seaThey have big eyes with more rods that detect more light in dark habitats.
EelsOceanic watersThey possess larger senses and increase the eyes’ diameter for clear vision with more rods and fewer cones for color.
SalmonStreamsPossess an enzyme called Cyp27c1 which can enhance the vision for longer-wavelength light, changing vitamin A1 to vitamin A2 and enabling the fish to see better and farther in shallow freshwaters.


Fish cannot see anything above the water, only a surface beneath, and it struggles to concentrate on objects that are directly above them. Although it depends on the levels of light above the water’s surface, ripples, and clarity of the water, the higher the fish is in the water, the more visible it can see. 

Their sight is dependant on their diet in that lower prey capture translates to a deficiency in Vitamin B1which is supposed to boost their eyesight. Their sight strength varies by species and age, and each perceives color differently. 

We hope you’ve gotten answers to your question and provided the much-needed insight on how fish see underwater. 

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