Certified Ophthalmic Technician (COT) Practice Test

The lens power indicated by the lensometry results points to a conclusion that the correct answer represents the appropriate prescription for the patient's spectacles. When lensometry shows a single line coming into focus first at -1.50, it indicates that there is a cylindrical component present. The appearance of multiple lines coming into focus after is indicative of a spherical equivalent, which is influenced by the cylindrical power. In this case, -1.50 seems to represent the spherical component, while the axis at 180 degrees confirms the orientation of any cylindrical power that may also be present. The fact that the answer reflects a power of PLANO-1.50x90 suggests that the lens has a spherical component of -1.50 diopters with a cylindrical component of -0.50 diopters at the 90-degree axis. This aligns with the lensometric findings because the power is expressed in a way that balances the necessary corrections in the vertical and horizontal orientations, which is common in prescriptions where astigmatism is present. Overall, this notation provides a complete picture of the patient's lens refractive error. The description of lens power demonstrates a correct understanding of how single and multiple lines correspond with different lens components during the lensometry process.