Which side effect associated with phenothiazines can cause visual disturbances?

Blurred vision is a common side effect associated with phenothiazines, a class of medications primarily used to treat psychotic disorders and nausea. This side effect arises due to the anticholinergic properties of phenothiazines, which can lead to changes in eye accommodation and pupil dilation, resulting in visual disturbances such as blurred vision.

While drowsiness is another well-known side effect of phenothiazines, it does not specifically refer to visual disturbances. Constipation, although possible with these medications, is related to gastrointestinal effects rather than vision. Granulocytosis pertains to the decrease in white blood cells, which can lead to an increased risk of infection, but it is not directly linked to visual side effects. Therefore, blurred vision stands out as the direct visual disturbance associated with the use of phenothiazines.