Certified Ophthalmic Assistant Practice Exam

What does pupillary distance help determine in spectacle fitting?

1. Frame size

2. Lens thickness

3. Alignment of optical centers

4. Weight distribution

The correct answer is: Alignment of optical centers

Pupillary distance is crucial in spectacle fitting because it measures the distance between the centers of the pupils of the eyes. This measurement is essential to ensure that the optical centers of the lenses are properly aligned with the wearer's pupils. When the optical centers of the lenses are misaligned with the pupils, it can lead to visual discomfort, reduced clarity, and potential eye strain. Correctly determining pupillary distance helps in customizing the fit of the glasses to the individual’s eyes, ensuring optimal vision and comfort. While other factors like frame size and lens thickness are important in the overall fitting process, they are not directly influenced by the pupillary distance. Similarly, weight distribution is a consideration for comfort but does not specifically relate to the optical function of the lenses in relation to the pupils.