How to measure eye sight with these five key points.
VISUAL ACUITY :
Visual acuity is the ability to see clearly and distinguish fine details. Snellen chart measures the visual acuity. It is a standardized chart that contains letters of different sizes. Viewing a chart from a specific distance usually 20 feet. The smallest line of letters that a person reads is their visual acuity.
Visual acuity is expressed as a fraction with the numerator being the standard distance at which the test is taken (20 feet). The denominator being the distance at which a person with normal vision could read the same line of letters. For example a visual acuity of 20/20 means that a person can read at 20 feet what a person with normal vision can read at 20 feet. A visual acuity of 20/40 means that a person can read at 20 feet what a person with normal vision can read at 40 feet.
PERIPHERAL VISION:
Peripheral vision which is the ability to see objects to the side while looking straight ahead. Visual field testing is a common method to measure peripheral vision. Person looks straight ahead at a central point while small lights are flashing in different areas of their peripheral vision. The person then indicates when they see a light. Allowing the examiner to map out the person’s visual field and detect any blind spots or defects.
COLOR VISION:
It is the ability to distinguish different colors. Testing of color vision uses a series of colored plates or pictures, such as the Ishihara test. In this test a person has to identify numbers or patterns hidden within a pattern of colored dots.
REFRACTION:
Another important aspect of eyesight is refraction, which is the ability of the eye to focus light onto the retina. Phoropter measures this ability. Phoropter, which contains a series of lenses that uses it to adjust the focus of light entering the eye. With these results prescription of glasses or contact lenses are recommended to correct any refractive errors.
HEALTH OF THE EYE:
It’s also important to measure the health of the eye during the eye exam. This includes looking at the front of the eye, including the cornea, iris, and pupil. As well as the back of the eye, including the retina, optic nerve, and blood vessels. This is done using a number of different instruments such as a slit lam. Which uses a beam of light to illuminate the front of the eye. Fundus camera, which takes a photograph of the back of the eye.
CONCLUSION:
How to measure eye sight using tests that evaluate visual acuity, peripheral vision, color vision, refraction, health of the eye. These tests help to identify any vision problems and determine the appropriate treatment like glasses, contact lenses, other corrective measures. It’s important to have regular eye exams to detect any vision problems early and maintain good eye health.