– What is Blepharo Plasty?
– What is Pthosis?
Optometry
A regular eye exam to check your vision or update your lens prescription for glasses.
Eye refraction is how the power of eyeglasses or contact lenses is calculated. This measurement is based on how much the lens of the eye has to bend light rays to process visual stimuli. This is expressed in a measurement of distance and clarity.
What Happens in a Refractive Eye Exam?
During an exam to test for refractive errors, your optometrist or ophthalmologist may conduct several tests to pinpoint the type of error that you have. Doctors prefer one or both of two standard tests—the visual acuity test and the retinoscopy exam.
Visual Acuity
Visual acuity measures how well each eye can see and focus. This test requires the patient to read letters on a chart placed 20 feet away, starting from the top row and with one eye closed at a time.
The rows (letters) get smaller down the chart, and the last one you’re able to read clearly indicates your level of vision clarity.
A positive refractive error diagnosis is confirmed if you can’t see the letters or symbols on line 20/20, which indicates normal visual acuity.
Retinoscopy
Retinoscopy involves the use of a hand-held instrument called retinoscope to narrow down the diagnosis to farsightedness, nearsightedness, or astigmatism. Before beginning this procedure, your optometrist may dilate your eyes to improve the accuracy of the test.
While moving the retinoscope light horizontally and vertically across each eye, the specialist observes reflection patterns off the retina. This test enables them to determine your exact type of refractive error.
Test results get evaluated, usually within a few minutes, to determine the best treatment plan to correct your eyesight. You can discuss potential remedies with your optometrist, such as glasses or contact lenses.
What Can a Test Find?
An eye refraction test not only tells a doctor if a patient needs corrective lenses (and what power the lenses have to be), it also tells a doctor if the patient has a number of conditions, such as:
- Astigmatism (a refractive issue based on the shape of the lens of the eye, which can cause blurry vision).
- Hyperopia (farsightedness).
- Myopia (nearsightedness).
- Presbyopia (inability of the lens of the eye to focus, related to changes in the structure of the eye due to aging).
Additionally, the results of the test can help diagnose:
- Retinal vessel occlusion (a condition that blocks the small blood vessels near the retina).
- Macular degeneration (an aging-related condition that affects central vision).
- Retinal detachment (when the retina becomes detached from the rest of the eye).
- Retinitis pigmentosa (a genetic condition causing retinal damage).