Which test is known to increase visual acuity in patients with uncorrected refractive errors?

The pinhole occluder is a useful tool in assessing visual acuity, particularly in individuals with uncorrected refractive errors. When a person looks through a pinhole, it reduces the size of the blur circle on the retina, allowing only the central rays of light to enter the eye. This effectively minimizes the effects of refractive errors such as myopia or hyperopia, leading to an improvement in the clarity of the vision for that moment.

This method is particularly valuable as it helps to differentiate whether the reduced vision is due to refractive issues or something more serious within the eye. If vision improves significantly with the pinhole occluder, it suggests that the decrease in visual acuity can potentially be corrected with appropriate lenses.

On the other hand, the visual field test evaluates the full horizontal and vertical range of vision, but it doesn't directly address issues of clarity caused by refractive errors. The color vision test assesses the ability to perceive colors and does not provide information regarding visual acuity, whereas the refraction test is used to determine the proper prescription for glasses or contact lenses but requires some understanding and is not a direct method for temporary improvement of visual acuity.