1031 British optometrists completed a questionnaire to give information on their rates of referral and notification to the medical profession. Data were collected in relation to the conditions concerned, the age and sex of the patient, and the spectacle correction. Major causes of referral were cataract, glaucoma, fundus changes, headaches/migraine/eye pain and lowered visual acuity; 6.5% of all patients seen were referred to their general medical practitioner notified, and of this group it was estimated that 25-30% could have managed with reading glasses which comprised spherical lenses of equal power. If such glasses could be self-selected, without reference to a medical practitioner or optometrist, a significant number of people would not benefit from the health screening aspects of the eye examination.