What is an important question to ask a patient who complains of a "red eye"?

In the context of a patient presenting with a "red eye," asking if they have blurred vision is crucial as it can help differentiate between various potential diagnoses. Blurred vision may indicate a more serious underlying condition, such as acute glaucoma, iritis, or even a corneal abrasion, all of which could necessitate prompt treatment.

For instance, if the patient does have blurred vision along with the red eye, it raises the suspicion of a more significant issue that could affect vision and may require urgent management to prevent permanent damage.

While the other options might also provide valuable information about the patient's condition, they do not directly assess for the immediate risk of vision loss, which is a primary concern when evaluating a patient with red eye symptoms. Hence, determining whether the patient is experiencing blurred vision is an essential step in the assessment process.