Yes, you can
Often times your cat will know if you are feeling bad.
The darker the room your cat is in, the larger it's pupils will get to allow more light into the eye. But I notice though, when my cat wants to pounce something, her pupils will get bigger also. A cats pupils change size not only because of light, but also because of mood. When prey (which if your cat is indoor might just mean a toy mouse) comes by, its pupils will dilate to get a better view of prey.
The cat will obiously walk in front of the thing or item they want and whine and meow for it until they get what they want.Well, my cat does anyway.
Animal pupils come all different shapes and sizes. A cat has slit shaped pupils, and a chicken has round pupils. Some goats even have time glass shaped pupils. Many different shapes.
Through a complex body language. If you want to know what they are feeling, see how they are acting. For example and angry cat will arch it's back.
The cat family of Panthera (leopard, lion, tiger, jaguar) have round pupils. Other cats including the cougar, snow leopard have vertical pupils.
Usually, if a cats pupils fill it's irises, it is scared. If their eyes are in slits, some people could say they're scared, but usually they're alert if they're slits. And, mostly when cats are happy, or relaxed, their pupils are fat slits, but not so they fill up their irises.
Cat's pupils enlarge when there is low light and when they are excited by something. Typically when they see something surprising or that they consider prey, their pupils will enlarge. There is no reason to think that they are seeing ghosts when this happens.
...that your cat is in a dark place. -_- (Also, it might be perturbed, especially if its ears are flat against its head.)
No nothing is wrong with your cat, her pupils are wide because when any object with eyes looks at a bright light, their eyes get small. But when it's dark, the pupils get big. So know you know why. :)
you can tell if your cat if fat is if her or she is lazy and chubby
A cat purrs when it is happy or is feeling safe.