Cats' eyes dilate primarily to adjust to different lighting conditions and emotional states. Their pupils widen in low light to allow more light into the eyes, enhancing their vision in the dark. Additionally, dilation occurs during excitement, playfulness, fear, or stress as part of their body's natural response to stimuli, helping them stay alert and focused. Persistent or unusually wide dilation can sometimes indicate health issues such as high blood pressure, glaucoma, or neurological problems, and should be checked by a vet if accompanied by other symptoms. Overall, dilated pupils are a normal part of how cats interact with their environment and express their emotions.
