Which factor is generally NOT considered when attempting to prevent poor fixation during automated perimetry testing?

In automated perimetry testing, ensuring accurate results requires careful consideration of various factors that influence a patient's ability to maintain a stable fixation on the target. The size of the fixation target, the patient's head position, and the duration of the test all play crucial roles.

For instance, the fixation target size is vital because a larger target can help patients with fixation difficulties maintain their focus more effectively. Similarly, the patient's head position is important to prevent head movements that can lead to inaccurate test results. Setting an appropriate testing duration helps manage fatigue and maintains the patient's ability to concentrate throughout the examination.

On the other hand, while screen illumination is important for the overall visibility of the test and can affect a patient's ability to perceive the target, it is not typically considered a direct factor in preventing poor fixation. Instead, proper management of target size, head positioning, and test timing are more critical in ensuring that the patient can adequately fixate during the perimetry test. Hence, screen illumination would be the factor that is generally not prioritized for preventing poor fixation in this context.