Question asked by Alex Aged 8

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

If you look at cats eyes in different lighting you will see that the shape of the pupil changes. In bright light the black pupil is very narrow. In poor light, or if the cat is nervous, excited or frightened the pupil is very large and round. Why ?

The coloured part of your cats eye is called the iris...and cats can have a wide variety of colours from blue, to green or yellow. The black part of the eye - the pupil - is actually a hole in the iris which allows light in to the back of the eye. If the circular muscle in the iris contracts the pupil size gets smaller - and this is to stop too much light getting to the back of the eye and damaging it. 


The slit-shaped pupils  seen in these cats is caused by contraction of the muscle.

These cats pupils are large pupils and, as they are in bright light (for the photograph to be taken ) they must be excited or frightened.

If you see a green, red or other coloured  glare from the eye that is due to light being reflected back through  the pupil from the the back of the eye..



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