Visual acuities serve as baseline data for the doctor. It sets criteria to achieve better vision for the patient. It helps determine if there is a refractive error or a pathology diagnosis. It’s important to understand the Snellen fraction when we report what the patient is seeing. Let’s take a look at the Snellen fraction. The numerator (20) represents the distance (usually feet) that the patient is able to determine what the image might be and denominator denotes the distance that the theoretical normal eye can see the image clearly. Techniques that can be used to obtain visual acuities are monocular: one eye at a time, binocular: with both eyes together, with correction and without correction and sometimes its necessary to use pinhole techniques or neutral density filters.