National Contact Lens Examiners (NCLE) Practice Exam

To determine the correct lens prescription for the patient wearing a -2.00 diagnostic soft lens with an over-refraction of -0.25 -0.50 x090, it's essential to analyze the over-refraction results and how they combine with the diagnostic lens. In this case, the patient initially has a base prescription of -2.00 diopters spherical. The over-refraction is measured as -0.25 sphere and -0.50 cylinder at axis 090. To find the final prescription, you need to add the over-refraction values to the base prescription. First, consider the spherical component: the base sphere of -2.00 and the spherical over-refraction of -0.25 results in a total spherical power of -2.00 - 0.25 = -2.25 diopters. The cylindrical component of the over-refraction indicates that the patient also has a need for additional correction in the form of a -0.50 cylinder power at a specific axis, but for this question, it primarily focuses on ordering the spherical lens appropriate for the overall refractive error calculated. Thus, considering the spherical adjustment, the appropriate power to order would be -2.25 sph, which effectively combines the adjustments made during