Inclusion Criteria:  Genetically proven family hypocholesterolemia patients, Patients systematically monitored in the Gastroenterology and Paediatric Nutrition department of the Women's Hospital Mother Child of Lyon or in the adult endocrinology department of the GHE (Louis Pradel Hospital), Girl/woman or boy/man over 6 years and over 12 kg at the time of inclusion (age required for cooperation on macular pigment measurement), No objection from the patient or their parents/legal tutors in the case of a minor patient, Patient covered by social security.  Exclusion Criteria:  Allergy to local anesthetics (especially xylocaine) Mydriatic allergy Person participating in another research with an exclusion period still in progress at pre-inclusion Person subject to a safeguard measure.