How does the owl see at night?

    There are all kinds of birds in the world and owl is one of them. what is peculiar about this bird is that it can see more clearly in the night than in the day. Its ears are also very sensitive. At night if there is a slighteset movement from any of its prey, it can detect and catch it very easily.

Its legs have four claws with curved nails which specially facilitate it to seize its prey. Mice are its favourite food.

    Owls are found almost in every part of the world. In some countries they are treated as inauspicious birds, while in some others they are regarded as symbols of wealth and wisdom. It is a bird that really comes to life at night and its whole body is especially suited to nocturnal activity. The birds having clearer vision in the night are called nocturnal birds. On the other hand the birds which can see clearly in day time are called diurnal.

    You must be very curious to know how this bird can see so clearly at night.

    To understand this, it is essential to know how we see the things. Light scattered by every object is focused on to the screen of the eyes by the lenses inside the eyes. This screen of the eyes is called the retina. An inverted image of the object is formed on the retina which is carried to the brain by optic nerve. This is erected by the brain and we see the object. The owl's eyes have four special features, due to which it can see more clearly in the night. Firstly, the distance between the lens of its eye and the retina is more than the distance in the case of our eyes. Due to this, the image formed on the retina is bigger in size. A special organ of its eyes named 'pecten' assists in focusing the lens i.e. in adjusting it for various distances. Secondly, the number of 'rods' and 'cones' (special cells) in the retina is very large-almost 10,000 per sq mm compared to 2000 per sq mm in our eyes. Thus, the owl can see five times more than us. Thirdly, its eyes have a red coloured material, chemically a prote,which makes its eyes more sensitive to light. Fourthly, the pupils of its eyes can dilate more, thus allowing even the smallest amount of light to enter the eyes. Due to these four factors, the owl can see more clearly in the night.