The canine or feline lens may become dislocated from its normal position within the patellar fossa posterior to the iris. This may be result of hereditary factors (predominantly abnormalities of the suspensory lens zonules and/or vitreous body), chronic intra ocular inflammation, vitreous syneresis, glaucoma and/or trauma. Posterior lenticular luxation may be partial (termed “subluxation”) or complete. Associated changes may include uveitis, varying degrees of cataract formation, the presence of degenerate vitreous material within the pupillary opening and/or anterior chamber and decreased or elevated IOP. Changes may be chronic or acute. Commonly affected breeds include multiple terrier breeds (Sealyham, Jack Russell Wire Haired Fox & miniature bull Terrier) the Australian Cattle Dog, the Chihuahua, Miniature Pincher & Springer Spaniel.