What is a common symptom of strabismus?

Double vision, also known as diplopia, is a common symptom of strabismus, which is a condition where the eyes do not properly align with each other. This misalignment can lead to the brain receiving two different images from the eyes, resulting in the perception of double vision, especially when looking at objects that are not directly in front of the individual. In strabismus, because one eye may focus on an object while the other does not, the brain may struggle to combine the images appropriately, leading to visual confusion.

The other options, while they may occur in various visual or eye-related conditions, are not typical primary symptoms of strabismus. Blurred vision often relates to refractive errors or other ocular conditions rather than the alignment issue specific to strabismus. Nausea can sometimes result from persistent visual disturbances but is not directly associated with strabismus itself. Similarly, headaches may occur in individuals with strabismus due to eye strain or fatigue from attempting to use both eyes together but are not a defining symptom of the condition.