Do You Really Need New Glasses? How an Eye Exam Determines the Right Prescription

It’s time for your eye examination. You may need a new prescription for your glasses or contacts. 

Our board-certified ophthalmologists and optometrist at Wolchok Eye Associates, PA, perform a thorough eye exam to determine whether your current prescription is still correct, or if you need a new one to see more clearly. 

If you already wear glasses or contacts, you have one or more of the following vision problems:

• Myopia
• Hyperopia
• Astigmatism
• Presbyopia

These are called refractive errors. Your eyes don’t focus light correctly because your eyeball or cornea is too short or elongated, or the vision problem is simply a result of aging. Your prescription glasses or contacts correct your focus to ensure light refracts correctly on your retina. 

The following are some of the important tests your eye doctor performs to ensure your prescription is correct for your eyes. 

Visual acuity test

You’re familiar with the test during which you read letters from a chart on the wall. Each line of letters gets progressively smaller. You read as many of the letters as you can on each line.

 What you can see is designated as a fraction, such as 20/40. Normal vision is 20/20. If your vision is 20/40, from 20 feet away, you can only see letters that are normally visible at 40 feet. This test provides a baseline of your current vision. 

Refraction Assessment

Next, your eye doctor uses a device that contains multiple lenses with different strengths. With one eye closed, you read the eye chart. Your doctor changes the lenses and asks which one makes the letters clearer. Your answers help your doctor choose the lens with the strength that corrects your vision to normal sight. 

Autorefractor and retinoscopy

Your eye doctor also performs a procedure called a retinoscopy to help determine your diagnosis of nearsightedness, farsightedness, presbyopia, and/or astigmatism. Your doctor shines a bright light into one eye at a time, moving the retinoscope in different directions while placing different lenses in front of your eye. 

Each one alters the direction of the light’s reflection. How the light reflects helps your doctor diagnose your refractive error. A device called an autorefractor also measures how light changes as it ricochets off your eye. 

Eye coordination and peripheral vision

We want to make sure your eyes track objects normally. We hold a pencil in front of you and move it in different directions, watching both of your eyes to see if they track the object correctly and to determine if you can see the object when it moves to the side. 

Eye disease check 

We also conduct tests to determine if you have signs of glaucoma, macular degeneration, retinal detachment, or other eye diseases. 

Contact Wolchok Eye Associates, PA, or request an appointment through our online portal today to ensure your eye health.