What percentage of cats with blue eyes are deaf?

White cats with two blue eyes have a 85% – 64.9%  chance of being deaf in both or one ear.  White cats with one blue eye have about a 40% chance of being deaf in both or one ear.  White cats with no blue eyes have about a 19% chance of being deaf in both or one ear.

Source: AETIOLOGY, PREVALENCE AND DIAGNOSIS OF DEAFNESS IN DOGS AND CATS by George M Strain published in this instance by Science Direct (the study).

The figures are surprisingly high. You can read more about deaf cats on these selected page:

• Deafness in Cats
• Deaf Cat
• My Deaf Cat Annabelle Had An Accident

If you use the search box you can see lots more....