Undervattenssyn

Undervattenssyn refers to the ability of certain animals to see while submerged in water. This ability is crucial for survival, aiding in navigation, hunting, and predator avoidance in an aquatic environment. The primary challenge for underwater vision is the difference in how light behaves in water compared to air. Water is denser and refracts light more than air, causing images to appear blurry and distorted to an eye adapted for air.

To overcome these challenges, many aquatic animals have evolved specialized adaptations. One common adaptation is a flattened cornea, which reduces the refractive power of the eye. Instead of relying heavily on the cornea, many underwater species have a more spherical lens that takes on the primary role of focusing light onto the retina. The size and shape of the eye can also be optimized for detecting prey or navigating in low-light conditions often found underwater. Some species, like dolphins and whales, can also adjust the shape of their lenses to fine-tune focus.

Another factor is the spectral composition of light underwater. Different wavelengths of light penetrate water to varying depths. Red light is absorbed quickly, while blue and green light travel further. Many aquatic animals have retinas sensitive to these specific wavelengths, allowing them to perceive their surroundings more effectively. Color vision underwater is also adapted to the light conditions, with some species seeing colors that are invisible to humans. The presence of a tapetum lucidum, a reflective layer behind the retina, is common in many marine animals, enhancing their vision in dim light by reflecting light back through the retina, giving photoreceptor cells a second chance to absorb the photons.