'Nuclear cataracts', or 'nuclear spots' as they are also known as, is not a Hereditary Cataract, according to an article I have just read by E. M. Bebbington BVSc MRCVS. This is seen as multiple spots along the suture lines of the nucleus and MUST be diagnosed by a specialist, not your ordinary vet, as your local vet can misdiagnose it. It is inherited, but isn't progressive, and can sometimes resolve itself and doesn't significantly affect sight. HTH