Is it true that moles are completely blind?

It is believed that moles, living underground in almost complete darkness, are blind or even have no eyes at all. We decided to check if this is true.

The opinion that moles are blind is so widespread that there is even a phraseology “blind as a mole». Questions about whether these animals are truly blind and why can be found in blogs, services questions And answers, on educational portals for children, websites about animals. Exists legend, that God deprived the mole of his sight because he spoiled the plants in the Garden of Eden. 

Despite popular belief, moles have eyes, but it's hard to spot them. not easy - they are very small, covered with wool, and sometimes even skin. Moles have really good vision limited, and animals are already born this way, and do not lose their sight due to living in the dark. This is explained by genetic characteristics: the lens in moles is not fully formed and consists of destroyed epithelium and an accumulation of immature cells.

However, scientists found outthat the organs of vision in moles still function. Researchers from the University of Aberdeen, who studied moles in Granada, Spain, for 25 years, note that they expected that the eyes of moles had atrophied during the process of evolution, since animals living in the dark do not need vision organs. But it turned out that moles have a fully developed retina, have all the types of cells necessary to distinguish between light and shadow, and the mechanisms for transmitting visual information to the brain work. Their eyes consisted from cells that perceive light (the so-called rods and cones). This structure is typical for diurnal mammals.

Indeed, despite the fact that moles have rather primitive vision, they perfectly capture light and shadow and can register the movements of objects. They have reaction photo-avoidance (behavioral) answer to a stimulus—in this case, light). That is, moles are really capable of seeing.

Mole eyes with their ability to detect changes in light serve animals as a biological clock. It is thanks to this that moles distinguish between day and night, and can also track the change of seasons. The breeding season of moles is from February to April, and they learn about its beginning precisely because of the change in the length of daylight hours.

Scientists carry out parallel with fish that live in caves at great depths - their organs of vision have indeed completely degraded as unnecessary. In particular, such fish have lost the gene PAX6, responsible for the correct formation of the eyes in their infancy. However, in moles this gene functions, but at some point, due to a mutation, it simply stops the formation of the eye. As a result, a “broken”, underdeveloped eye is formed, which is nevertheless able to distinguish light from darkness.

In addition, moles use eyes to detect magnetic fields. So, scientists conducted experiment, surgically removing the eyes of experimental moles. In everyday life - while feeding, communicating with relatives, moving - they behaved exactly like those moles that had eyes, because they use vision for this little. However, the experimental animals began to dig holes in random places, while usually the species under study preferred the south-eastern direction. Scientists have linked this to the fact that moles determine the cardinal directions with their eyes. So far, scientists have not established how exactly this mechanism works, but, of course, moles do not see them in the literal sense of the word.

At the same time, moles successfully compensate for poor vision by developing other senses. They are incredibly spicy stereophonic scent - each nostril can capture and process information independently of the other. Touch - another tool for orientation in space and knowledge of the surrounding world, which is developed in moles much better than in many other mammals. Besides it turned outthat they remember and begin to navigate freely in mazes much faster than field mice with acute vision.

Thus, moles really rely little on vision in everyday life, using mainly their sense of smell and touch. They have eyes, and although they see very poorly, they cannot be called completely blind. These animals have all the mechanisms necessary to perceive and transmit visual information to the brain, thanks to which they distinguish between light and shadow, detect the movement of objects and track the changing seasons based on daylight hours, which is associated with changes in their behavior.

Mostly not true

What do our verdicts mean?

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