Objective: To study non-tolerance to spectacle prescriptions in a tertiary eye care hospital. In recent years, there has been an increased emphasis in the healthcare services on clinical governance and on causes of adverse reactions. This study was an evaluation of non-tolerance cases in a large volume optometric practice. The main aim was to determine the most common reasons for a patient to return un-satisfied with their new spectacles. Methodology: The project was based at a busy community optometric practice in Dr Shroff's Charity Eye Hospital, Delhi., Prescription non-tolerance was defined as a patient who had collected spectacles from the optical, agreed to try them in their habitual environment, but had subsequently returned within 1 month because they were either having problems with, or were unable to wear, their new spectacles. If the non-tolerance persisted or the spectacle dispensing was felt to be correct, the patient was sent for a retest or non-tolerance examination with an optometrist. Where possible, this was arranged with the initial prescriber. Inclusion criteria: We were included those patients who were more than 18 years. The fitting of the frame, inappropriate type of lens (e.g. single vision bifocal or progressive addition lens), positioning of lens (e.g. bifocal at incorrect height) and wrong refraction were considered for study. Exclusion criteria: We were excluded those had pathological condition and developmental disabled. Result: A total of 5715 Spectacles dispensed during the 15 month study period. Of these, 47 were non tolerance examinations, which accounts for 0.82% with 95% CI LL 0.59% and with 95% CI UL 1.06% of eye examinations. Conclusion: In summary, non-tolerance examinations comprised a 0.7% of eye examinations. In a climate where clinical governance and auditing are increasingly important, an understanding of the norms for prescription non-tolerance can help optometrist to determine best practice.