has she never had her jabs? even if she is in the house, you still bring germs etc into the house..big risk..
The only option you have is to take her to the vets. In an elderly cat it could be serious. Whether or not she has ever been out of the house she needs medical attention. Now not later.

Ok im a pest i no    but i have this problem with my cat(10 nearly 11yrs old) every now and then her eyes goes still and she starts dribbling then shakes and licks and i being worried for no reason or is these fits? i dont want to take her the vets as shes never been out  the house(cept when we had her and when we moved) and shes never been the vet