Russian Blue — questions to ask before paying a deposit
A responsible breeder will have these readily available. Deflection is a red flag.
Hereditary cataracts
A pedigree study of Russian Blues found bilateral cataracts in around a third of the cats examined — usually small and not affecting vision, but occasionally more extensive and causing visual impairment or blindness. No causative gene has yet been identified, so there is no DNA test; screening relies on a veterinary ophthalmologist examining the eyes directly.
Ask to see: No DNA test exists (the causative gene has not been identified). Ask for a veterinary ophthalmologist's slit-lamp examination result for both parents.
Nygren, Jalomäki, Karlstam & Narfström, 2018, "Hereditary cataracts in Russian Blue cats", Journal of Feline Medicine and Surgery (https://journals.sagepub.com/doi/10.1177/1098612X17752197)