Lens luxation is a condition reported in a variety of dog breeds and is presumed to be genetically controlled. Although Parson Russell Terriers exhibit a predisposition for this disorder, little is known about the inheritance of lens luxation in this breed or in many of the other 35-46 purebred dog breeds afflicted with this disorder. Additionally, Parson Russell Terriers are reported to exhibit juvenile cataracts. Again, the heritability and mode of inheritance for juvenile cataracts are unknown for the Parson Russell. The objective of this study is to collect sufficient pedigree and phenotypic data for eye anomalies in Parson Russell Terriers to establish heritability and mode of transmission for primary lens luxation and juvenile cataracts. All data will be handled confidentially. Concurrent with the pedigree and phenotypic data collection, we will request cheek swabs to be submitted for DNA extraction. Thus, if the mode of inheritance suggests that identifying a genetic marker linked to either lens luxation or juvenile cataracts is possible, then the stored DNA could be screened in the future with a battery of microsatellite markers or markers representing candidate genes.