If a cat’s pupils are circular, it is likely that

It is looking at a fire

It is walking in darkness

It is pleading for food

It is about to sleep

Why Are Cat Pupils Circular When They See in Darkness?

Cats have remarkable eyes that adjust to different lighting conditions by changing pupil shape. If you notice a cat’s pupils are fully circular, it is mainly because it is walking in darkness or very dim light. This article explains why this happens and the meaning behind other common myths related to cat pupil behavior.

What Does a Cat’s Pupil Shape Tell Us?

Cats’ eyes are equipped with vertical slit-shaped pupils in normal or bright light, which help regulate the amount of light entering their eyes precisely. But in near darkness, the pupils dilate fully to become large and circular. This maximizes the light intake, enhancing their night vision.

• It is walking in darkness:
  This is the correct explanation. When a cat is in low light, its pupils open wide and become circular to allow as much light in as possible. This adaptation helps cats see better in the dark, which is why their pupils appear perfectly round.

• It is looking at a fire:
  This is unlikely to cause pupils to become circular. Fire can create a flickering, bright light that might cause a cat’s pupils to constrict or remain slit-like to protect its sensitive eyes from excessive brightness.

• It is pleading for food:
  Pupil shape doesn’t usually correlate with emotional states like begging. While cats use body language and vocalizations to plead for food, pupil dilation mainly depends on light levels and arousal, not specifically food begging.

• It is about to sleep:
  Before sleeping, a cat usually has relaxed and partially closed eyes, without distinct pupil dilation. Circular pupils are more an indication of visual needs rather than sleepiness.

Understanding Cat Eyes: A Quick Guide

Cat pupils change shape primarily in response to lighting:

• Bright light: pupils contract to vertical slits to protect the retina and sharpen focal depth.

• Dim light: pupils dilate fully, becoming round, to let in ample light.

• Emotional arousal or fear can cause pupil dilation but does not usually change the slit shape to perfect circles in the presence of normal light.

Conclusion

A cat’s pupils turning circular is a natural reflection of its need to see well in darkness. This biological feature allows cats to be excellent nocturnal hunters and explorers. So if you see those large, round pupils staring at you, it’s likely just your feline friend adjusting its vision for the dark.