My cat has a white film on its eye and is lethargic. Is it serious?

Hello there,

This white film is the third eyelid. This can be raised for eye pain, conjunctivitis, infections, or herpes viral flares. I also see that Gussie's eye is being held closed. This is called blepharospasm and is a sign of pain. Many cats will become lethargic during viral flares, so if Gussie has experienced herpetic conjunctivitis flares like this before it may be a self resolving situation. I do always recommend using some type of lubricating +/- antibiotic ointment or drop on their eyes during these flares to prevent an ulcer or serious secondary infection from occurring, as well as for pain relief and faster healing.
These flares commonly occur during times of stress, such as a move or a new person or pet in the home. However, these flares can also be a signal of underlying immune suppression, such as that from disease or cancer.

I'd recommend having Gussie seen by his vet tomorrow so that you can be sure there is no underlying disease predisposing to this. Hopefully it will just be an exam and picking up some eye medications for him.