Interestingly enough, in our versatile animal kingdom, there are multiple animals that are born blind. One of them is the eyeless shrimp, which only has light perception. Another one is the star-nosed mole, the fastest-eating mammal in the world, who uses touch as their main sensory organ.
Many species of mammals, such as rabbits, are actually born blind (born with their eyes closed and eyelids fused together), with their eyes opening a little while later. Of course, treatment exists for animals with blindness, however, not to the extent that it does with humans.
The early weeks: dominated by inherited behaviour Kittens are born blind and deaf. Right from the start, however, they react very sensitively to tactile stimuli such as being cleaned by their mother.
The altricial pigeon is born blind with a transient glycogen cataract.
Most mammals have good vision, yet some species have naturally evolved poor eyesight: mice and rats, for instance, have very poor eyesight, while species like the naked mole rat have lost their vision entirely.
Snakes are therefore likely to be dichromatic in daylight, meaning they see two primary colours compared to the three that humans see. Most snakes examined in the study are sensitive to UV light, which allows them to see well in low light conditions.
Hares are born with their eyes open, hair covering their bodies, and they can run within a few minutes of birth (much like a Guinea pig!). Rabbits, on the other hand, are born blind, naked, and remain in a fur-lined nest for the first days of their lives.
Blind mole rats appear eyeless and earless, as the functioning remnants of these structures are covered by fur and are therefore not visible. The tiny eyes are hidden beneath the skin, and the external ears are reduced to slight folds.
They react differently when external stimuli are applied while sleeping and while awake. But the bullfrog, Lithobates catesbeianus show the same reaction in both situations. This indicates that bullfrogs do not sleep. Lithobates catesbeianus is an animal that cannot sleep.
In addition to beetles and bees, a number of other animals are now known to see remarkably well in dark environments: cockroaches, lantern fish, cuttlefish, frogs and nocturnal primates such as owl monkeys. So neuroscientists are turning to the question of how they do it.
#8: Snakes are deaf
Although they lack eardrums, snakes possess inner ears which are able to pick up not only ground-borne vibrations but low frequency airborne sounds. They do have difficulty with sounds at a higher pitch.
Hainan Gibbon (Nomascus hainanus)
The stunning Hainan gibbon is the rarest ape in the world – and probably the rarest mammal – with a total population of around 25 individuals.
Some dogs are born blind while others develop blindness over time from age and disease. No matter the situation, blind dogs are just as loveable and playful as dogs with excellent eyesight.
Tiger cubs are born blind and are completely dependent on their mother. Newborn tiger cubs weigh between 785 and 1,610 grams (1.75 to 3.5 lb). The tiger cubs' eyes will open sometime between six to twelve days. However, they do not have their full vision for a couple of weeks.
Rabbits are naturally very clean animals and do not like their toilet to be anywhere near their food or bedding area (just like cats!). They will happily use a litter box — and in the right environment, are quite happy as 'house bunnies'.
After a gestation period (time between mating and birth) of 28 - 31 days, a litter of 3 - 8 babies is born. At birth they are blind, deaf, hairless and hardly able to move for their first week.
Why do rabbits have red eyes? Red eyed rabbits occur as a result of albinism. With a couple rare exceptions, the rabbit's bodies are entirely devoid of color. The appearance of the red eye comes from a reflection of the inside of the rabbit's eye, not the color of their iris.
Snails, jellyfish slugs, and worms are some examples of animals that do not produce sound to communicate.
Experiments have suggested that cattle can only discriminate long wavelengths of light (colored red) from short (blue) or medium (green) wavelengths, and not short from medium wavelengths; however, stimuli were inadequately balanced for intensity.
The box jellyfish (Tripedalia cystophora) is far from a simple blob with tentacles. It's an active, manoeuvrable predator, and it finds its way around with no fewer than 24 eyes. Scientists have known about these for over a century, but people are still trying to work out what they do.
The tuatara has a third eye, as do some other reptiles. But this adaptation has been lost in the radiation into later orders such as crocodiles, birds, and mammals, although remnants of this organ can be found in most of these. The third eye, then, represents evolution's earlier approach to photoreception.
The visual system of an ant is comprised of a pair of compound eyes and a set of simple eyes called ocelli.