Which test is known to potentially increase visual acuity in a patient with an uncorrected refractive error?

The pinhole occluder is known to potentially increase visual acuity in patients with uncorrected refractive errors. When a patient looks through a pinhole, it allows only a narrow beam of light to enter the eye, effectively reducing the effects of refractive errors such as myopia or hyperopia. This helps to focus the light more accurately on the retina, leading to improved clarity of vision. The pinhole effect does not correct the refractive error, but it helps to demonstrate what the visual acuity could be if the error were corrected.

This characteristic makes it particularly useful in clinical settings to determine whether a patient's reduced vision is due to a refractive error that could be corrected with glasses or contact lenses. In contrast, the other options listed are not designed to improve visual acuity in this manner; they serve different purposes in the assessment of visual function or alignment.