Successful dispensing depends on more than accurate prescriptions alone. Frame selection, adjustment and as-worn positioning all influence the accuracy of spectacle measurements and ultimately determine wearer comfort, visual performance and adaptation success. This CPD explores the relationship between frame fit and spectacle measurements, examining how factors such as pantoscopic tilt, vertex distance, frame stability and fitting position affect dispensing outcomes.Topics include:1. The importance of correct frame fitting prior to measurement 2. Key dispensing measurements and their clinical significance 3. The impact of frame adjustment on as-worn positioning 4. Considerations for high prescriptions, multifocals and paediatric dispensing 5. Clinical case studies demonstrating how frame fit and measurement errors contribute to non-toleranceTwo clinical case studies illustrate how measurement errors present in practice and how they can be identified and resolved. Measurements are only meaningful when taken on a correctly adjusted frame in its intended wearing position.