What range of diopters can the BL keratometer measure?

The BL keratometer is designed to measure the curvature of the cornea and is commonly used in fitting contact lenses as well as in pre-operative assessments for refractive surgery. The correct answer, which indicates a range of 36 to 52 diopters, reflects the typical specifications of general-purpose keratometers. These devices are calibrated to measure within this range, accommodating the average corneal curvature found in the majority of patients.

This range is particularly important, as it allows practitioners to gather accurate measurements needed to determine proper lens fitting or assess the need for refractive procedures such as LASIK. Measurements below or above this range may fall outside the device's capability, making it ineffectual for precise assessments in those cases. Therefore, understanding the operational limits of the BL keratometer is key in ensuring effective patient care and interventions in optometry.