Eyes and vision
Did
you know that the volume and weight of a cat’s eye in relation
to that of its body is greater than that of any other mammal?
The
eye of the cat is situated at the front of the head, as with humans,
which means that they have to turn around to see behind them.
The total vision of the cat is 280 degrees, wider than that of
humans (220 degrees), and is even wider than that of dogs. Another
characteristic of the cat eye is that the iris, the coloured part
of the eye, presents a great variety of colours – shades of green,
yellow, mauve and orange. The pupil of the cat also varies dramatically
in shape and size according to the intensity of light. In bright
light it shrinks to become a mere slit. The cat’s eye also has
exceptional sensitivity to light and, therefore, cats enjoy good
twilight vision. Contrary to popular belief, cats cannot see in
total darkness. In fact, if it can move in the dark, it is thanks
to its "radar" whiskers.
When
it comes to detecting movement, the vision of the cat is extremely
acute. The eye reacts almost instantaneously, immediately focusing
on the moving object, prey, evaluating size, distance and any
obstacles in the cat’s path to it. The merest quiver, suggesting
the presence of possible prey, registers on the eye and this is
the cat’s chief hunting tool. The prey has only one means of escape
from the constant vigilance – to freeze completely ("play dead").
Do cats have color vision?
This
is a commonly asked question. Cats cannot see as many colours
as humans can. They can distinguish between certain colours, including
different shades of blue and greenish yellow. Cats cannot see
orange and red; these colours appear white to the cat.
When
kittens are born, they are blind. They do not open their eyes
until they are seven to ten days old. For the first three months,
their vision is significantly weaker than that of humans; however,
it develops and is refined as they age.
The
cat’s vision usually remains excellent well into old age. Some
cats do go blind, usually as a result of illness or injury.
The
eye of the cat is often an indicator of its emotions. If angry
or sexually aroused, its pupils often dilate; whilst being stroked,
it may blink with pleasure.
Caring for your cat's eyes
As
with any animal, the eye is a very delicate organ and should be
treated with the utmost care. Minor irritations should never be
ignored as these can deteriorate rapidly and may result in irreversible
damage. You should never leave any eye problem untreated for longer
than 24 hours. If treatment has been commenced, your veterinarian
should be consulted if the eye does not begin to improve within
24 hours.
Cats
sometimes acquire a foreign body in their eye, for example, a
small splinter. It is important to take great care when trying
to remove any foreign body from the eye. First, place the cat
under a good light. Roll the eyelid away from the eyeball with
both thumbs. Most cats will not allow you look under their third
eyelid (this is the small flap in the corner of the eye) but you
should be able to see if there is anything protruding from the
under its edge. It may be possible to remove a large foreign body
with your fingers; small foreign bodies may be removed by flushing
the eye or gently wiping with a dampened swab. If you cannot remove
the foreign body, consult your veterinarian immediately.
