American Board of Opticianry (ABO) Practice Test 2025 - Free ABO Practice Questions and Study Guide

The optimal angle of the temple arm in relation to the frame front is approximately 90 degrees. This angle is crucial for achieving a secure and comfortable fit of eyewear on the face. When the temple arms are set at this angle, they can effectively hold the glasses in place, ensuring that the lenses are properly positioned in front of the eyes for clear vision.

A 90-degree angle also allows the temple arms to sit comfortably against the sides of the head, preventing slippage while the wearer is active. Additionally, this angle helps in distributing the weight of the glasses evenly across the nose and the ears, enhancing overall comfort during prolonged wear. This positioning is essential for avoiding pressure points that can lead to discomfort or headaches.

In contrast, other angles such as 45 degrees would potentially cause the eyewear to sit unsteadily, leading to misalignment of the lenses and possibly affecting vision clarity. A typically straight temple arm could indicate a poor fit for curvilinear head shapes, which might also lead to discomfort and improper lens alignment. An angle ranging from 80 to 100 degrees may not provide the necessary stability or comfort that a precise 90-degree angle offers, risking movement and the need for frequent adjustments.