What is one of the key examinations performed by an ophthalmologist?

Visual field testing is a critical examination performed by an ophthalmologist to assess a person's peripheral vision. This test helps detect any changes or loss in vision that may indicate underlying health issues, such as glaucoma, retinal diseases, or neurological disorders. Ophthalmologists utilize this testing to evaluate how well the visual pathways are functioning from the eyes to the brain. It is an essential tool in their clinical practice, allowing them to make informed decisions about diagnosis and treatment.

The other options, such as routine blood tests, cholesterol screening, and urinalysis, are more commonly associated with general health assessments or primary care rather than being specific to ophthalmic evaluations. These tests focus on different aspects of health that aren't directly related to eye conditions or vision.