How often does the patient read in a way that causes them to experience blurry vision?

The patient reports that they only experience blurry vision during long reading sessions, indicating that this issue is associated with prolonged visual strain or fatigue. This type of visual discomfort often occurs when the eyes are focused on a task for an extended period, particularly without appropriate breaks or changes in focus.

In the context of reading or other close-up activities, prolonged engagement can lead to symptoms like blurry vision due to a condition often referred to as digital eye strain or computer vision syndrome. This aligns with the correct answer, as it highlights a specific condition rather than an ongoing or frequent occurrence. Understanding this can also serve as a basis for educating patients about the importance of taking breaks and practicing good visual hygiene, especially during intensive reading sessions.

Other choices suggest either more frequent occurrences of blurry vision or none at all, which do not accurately reflect the nature of the patient's experiences as described.