What is an Eye Exam?
An eye exam is several tests given by an optometrist or ophthalmologist. The doctor tests for vision quality and the ability to focus on different objects. Other tests are performed in an eye exam such as a pupillary reaction test, cover test, refraction and retinoscopy test. Professionals recommend to have a vision screening as a part of routine healthcare especially if the patient is at risk for eye diseases or systemic diseases.
Visual Acuity
A visual acuity test measures how sharp the eye sees. The doctor will evaluate vision while the patient sits 20 feet away from an eye chart and reads the letters. The last line of the smallest letters a patient is able to read is marked down as their visual acuity. Normal vision is 20/20. Vision less than 20/20 is the distance needed to move up to see properly. For example, a person with 20/60 vision would need to move up 20 feet to see what a person with normal vision reads from 60 feet away.
Pupillary Test
A pupillary test measures how well the pupils react to light. Testing how the pupils react to light can reveal serious conditions like concussions or neurological problems. Light is directed into the eye and the reflex reaction is noted by the doctor. The swinging flashlight pupil test compares different responses to light by flashing the light from one eye to another noting how each pupil reacts.
Cover Test
A cover test measures how well the eyes work together. The goal is to measure how well the eyes fix on an object near or far. The test requirement is for one eye to be covered, a pause, and uncovering the eye. The doctor evaluates how the eye looks as it's uncovered and fixates again on the object. The cover test diagnoses cross eyes, lazy eye and lack of perception.
Refraction and Retinoscopy
Retinoscopy testing allows the doctor to measure refraction. Retinopathy is a starting point of measuring glasses. It is an examination of the retina. Refraction is the examination part of the exam where the doctor asks "which lens is clearer, one or two?" Refraction tests for presbyopia, farsightedness, astigmatism or near sightedness.