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Fun facts

Q. 1 Why can animals like cats, owls see well at night?

Q.2  Do dogs enjoy a coloured television?


Q.3  Can butterflies see more than human beings?

Q.4  How do insects see?

Q.5  Who has the sharpest eye?

Q.6  We do not see some colours in flowers. Is this true?

Q.7  Is there a third eye?

Q.8  Is there a third eyelid?

Q.9  Do some birds have a third eyelid?

Q.10 What is perception of vision?

Q.11 Why do animal eyes appear red in dark?

Q.12 What is the 'red eye' in a photo?

Q.13 Which animal cannot cry and cannot blink?

Q.14 Do some animals have no eyes?

Q.15 Man is known by the company he keeps. Is it the same for color too?


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1.Why can animals like cats and owls see well at night?

Nocturnal animals like owls have greater density of rods in their retina. The rods are responsible for vision in dark. Therefore they see better at night. Owls also have tubular eyes that increase  the throw from the lens to the retina.

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2.Do dogs enjoy a colored television?

Unfortunately, your doggy cannot enjoy your colored television! Dogs have very poor color vision. So they see in shades of grey, just like a black and white television.

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3 Can butterflies see more than human beings?

You may feel insulted, but that is true! Butterflies have compound eyes like many other insects. They see better than humans in ultraviolet range upto 300 nm. They require this ability to spot the central nectar bearing part of the flower. The flowers have a more colorful center, than what we can appreciate! This helps the plant in pollination.

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4.How do insects see?

Insects have compound eyes. Each eye has many shiny lenses, which cast a small image. These multiple images are integrated by their 'brain' and the object is seen. Unlike our lens, these lenses cannot focus. Compound eyes are advantageous to insects since they provide a better field of vision, so enemy or prey can be seen in all directions.

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5 Who has the sharpest eye?

The hawk has the sharpest eye. Its eye has two foveae and the maximum concentration of cones.

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6 We do not see some colors in flowers. Is that true?

That is true, though flowers look vividly colored, yet they are better than they appear! The flowers like daisies, dahlia have an attractive colored zone around center. This zone is does not appear different from the surrounding color to us, but the butterflies can see more colors in that zone. This is a special gift to the butterflies, since they have taken up the job of pollination

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7.Is there a third eye?

Third eye is a very popular mythological concept. Did you know, the tumor Retinoblastoma can arise in the pituitary gland too? The Pituitary, is an endocrine gland that lies on the under surface of the brain. During development in the embryo, it lies very near the eyes, later ascends into the brain. Thus it can be considered as a third eye. In Yoga, it is considered as one of the important 'power centers'! Some animals like certain lizards and snakes have a 'third eye', located in the center of forehead. This controls body temperature in response to light, rather than actually see. 

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8 Is there a third eyelid?

Some animals do have a third eyelid, for e.g. the frog, has a thin membrane which it pulls up over its eyes, when in water. We have a third eyelid in the form of the red triangular fold on inner side of the eye, called 'caruncle'.

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9.Do some birds have a third eyelid?

The Ouzel also called the American Dipper has a third eyelid. It feeds on larvae and insects in water. It swoops into the water and puts on its swimming glasses, its third eyelid covers its eyes! It also has oil flaps of skin on the nostrils to prevent water entering its nose, while it flies inside water!

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10 What is perception of vision?

When the frequency of movement is more than 10 in one second, we see a continuous motion. This is called as perception of vision. This is made use of in motion pictures. The pictures are cast on the screen so fast, they appear continuous.

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11.Why do animal eyes glow in dark?

In dark, the pupils are dilated, so that maximum amount of light enters the eye. When suddenly, light is shone in the animal eyes, it is reflected from the Tapetum lucidum. This is the reflecting layer behind their rod-rich retina. That is the reason, why the animal eyes glow in dark.

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12.What is the red eye effect in a photo?

The red eye in the photo, is because, the light when shone from a certain angle gets reflected from the choroid. The choroid has many blood vessels and therefore appears red. The 'red eye effect' can be avoided by changing the direction of the camera.

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13.Who has no eyelids?

Fish! They do not have eyelids. They do not require tears either, since their eyes are bathed by water, no special lubricant like tears is required.

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14.Do some animals have no eyes?

Some salamanders that live in dark caves and certain fish that live near deep Ocean beds have no eyes! This is because they do not need eyes, since in light never ever reaches them! Some of them have rudimentary eyes with permanently closed eyelids over them, while in some the eyes are totally absent.

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15.Man is known by the company he keeps. Is this true for colors too?

Color is sensed by the cones in the retina. The color of the surrounding affects the perception of color. Which circle is darker? 

Figure :


         They are the same shade, just in different backgrounds!

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