Visual Acuity: Understanding and Meaning
Visual acuity, also known as visual acuity or simply visual clarity, is an important aspect of vision that determines a person's ability to distinguish details and see objects clearly at a certain distance. This indicator is measured as a fraction, where the numerator corresponds to the distance at which the object is visible, and the denominator corresponds to the distance at which the object can be seen by a person with normal vision.
Visual acuity depends on several factors, including the condition of the cornea, lens, retina and optic nerve. Good visual acuity is only possible with optimal functioning of all these elements. Any disturbance in the structure or function of these components may result in decreased visual acuity.
Visual acuity is determined using special tests that measure a person’s ability to see and distinguish certain details. The most common test is the test of identifying letters or symbols at a certain distance, known as the Sniellen test. During this test, a person must read letters or symbols at a certain distance, and the results are then compared with the norm to determine the level of visual acuity.
Visual acuity is measured in diopters. A person with normal vision has a visual acuity of 1.0 (or 20/20 according to the Snellen system), which means that they can see objects at a distance that the average person can see at 20 feet (6 meters). If visual acuity is less than 1.0, it indicates problems with vision, and the lower the value, the worse the visual acuity.
Deterioration in visual acuity can be caused by a variety of reasons, including refractive errors such as nearsightedness, farsightedness and astigmatism, and age-related changes such as age-related farsightedness (presbyopia). Other factors such as glaucoma, cataracts, and degenerative retinal diseases can also affect visual acuity.
It is important to note that maintaining good visual acuity is a key aspect of overall eye health. Regular visits to your optician or ophthalmologist will help identify and treat any vision problems, which will in turn help you maintain optimal visual acuity.
Visual acuity is an integral part of our ability to see and perceive the world around us. Take care of your eyes, follow your doctor's recommendations, and monitor your vision to maintain good visual acuity throughout your life.