The eye is one of the most complex organs in the human body. In order to gain a full understanding of the eye, many different tests and observations must be administered.
Most comprehensive eye tests take up to two hours, based on the optometrist’s observations. Here’s what to expect from the typical comprehensive eye exam:
Visual Acuity Test
A Visual Acuity Test is an exam that measures your ability to recognize letters or numbers of varying size from different distances. Results of visual acuity tests are represented as fractions.
A score of 20/20 indicates that your visual acuity at 20 feet away from the object is normal. A score of 20/40 means that you need to be 20 feet away to see an object that most people can see from 40 feet.
Retinoscopy uses a Retinoscope, an instrument that shines light into the patient’s eyes. This process allows the optometrist to observe the reflex of the patient’s retina and measure the amount of refractive error of the eye.
Refractive Error occurs when the shape of the eye affects how accurately your eye can focus light. Common types of refractive error are near-sightedness, far-sightedness, or astigmatism.
The measurement made by Retinoscopy is vital to finding the right prescription for you.
Retinoscopy is used to measure objective refraction without any feedback from the patient. There are other types of refraction test that can be performed:
The patient sits behind a phoropter or wear a trial frame to determine which lens is the most effective. The optometrist requires feedback from the patient to determine the best lens.
Keratometry is the measurement of corneal curvature. Corneal Curvature determines the power of the cornea. This measurement is mostly important for determining the magnitude of astigmatisms, increasing the likelihood of your prescription being perfect.
Tonometry measures your inner ocular pressure. Before tonometry, eye drops are used to numb your eye to minimize discomfort. Then an optometrist or technician will use a tonometer to measure the inner pressure of the eye.
This method can be used to identify glaucoma, and scan for many other eye problems.
Slit Lamp Exam
Also known as Biomicroscopy. You will be resting your chin and forehead in an instrument during this examination. The doctor will use a low-powered microscope and a slit lamp to look for any possible conditions that other tests cannot observe.
This test is very important for discovering any diseases of the eye.