This article contains a literature review on FHV-1-related ocular diseases in cats and a fi eld study of ocular diseases in cats. We studied the prevalence of ocular (conjunctival, corneal, lens and retinal) abnormalities in cats and the connection of abnormal fi ndings to FIV, FeLV and FHV-1 infection. We also estimated the reliability of FHV-1-PCR test from conjuctival swabs. We studied 115 shelter cats in Helsinki, Finland. Complete eye examinations (biomicroscopy, indirect ophthalmoscopy and, if needed, Schirmer’s tear test and tonometry) were performed on all cats and they were tested for FIV and FeLV. A sample for the FHV-1-PCR test by conjunctival swab was taken from 25 cats with clinical signs indicative of FHV-1 infection (FHV-1-related ocular disease and/or symptoms of upper respiratory infection). Of the total of 115 cats tested, 3 were positive for FIV and none for FeLV. Of the 25 cats tested by PCR, 7 were positive. There was a statistically signifi cant (p = 0.008) correlation between FHV-1 infection and upper respiratory infection. Cats with active upper respiratory infection and ocular disease tended to be positive for FHV-1 on PCR, whereas cats without active upper respiratory but with ocular disease tended to have negative PCR results. As cats with chronic ocular diseases related to FHV-1 may be negative on PCR, this disease should remain in consideration if clinical signs and history are consistent with FHV-1 infection.