Published in Primary Care

Reflections on the Art of Refraction

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10 min read

Refraction is a staple in the optometrist's toolkit, this article outlines pearls for optimizing measurements and patient communication to improve the experience.

Reflections on the Art of Refraction
It’s 2024, and it’s an exciting time to be an optometrist. We are physicians poised to manage a range of ocular and systemic pathology with a scope that’s never been broader.
We’re managing glaucoma, dry eye, and diabetic retinopathy. In some states, we’re performing laser treatments and minor surgical procedures.
Whether you love it or hate it, one thing is undeniable, optometrists are known for the phrase, "Which is better, 1 or 2." In optometry school, I got the sense that bread-and-butter optometry is, well, vanilla.
However, as a private practice doctor doing a lot of refractions, I’ve learned to appreciate and hone this skill. Some docs see refraction as a monotonous exam element. Yet, let’s take a step back and reframe.
When you refract, I want you to think of yourself as a magician bending light. Don’t forget what we are doing here—optimizing one of life’s treasures: the gift of sight.

Cataracts, accommodation, and dry eye…oh my!

Increasingly, eyecare practices have started to delegate the mechanical act of refraction to a trained technician. This can improve efficiency and allow the doctor more face-to-face time with the patient.
The problem with that is this—we are not machines, and neither are our patients. If you’ve done enough refracting, you quickly learn that it is anything but mechanical. It’s VERY personality (and mood!) dependent.1 Beyond that, there are so many factors that make this test harder.
For example, the internal monologue of your patient with cataracts likely goes: "It’s blurry. Is it supposed to look this bad? Wow, this optometrist must be bad at their job. It’s STILL blurry. They’re asking me to read that row?" Little do they know of the grade 2 cataracts filtering all that deliciously crispy light into a fuzzy "I can read it, but…"
Review the patient’s chart before starting refraction. Putting up a larger row at the beginning for patients with even mild cataracts can greatly increase the patient’s confidence and performance from the start. I like to start with a single row that is about two lines above the entrance visual acuity (VA) to build confidence.

How dry eye and accommodative dysfunction impact refraction

Similarly, an unstable tear film in dry eye can cause a shifting cylinder axis and varying responses from the patient.2 Instilling artificial tears before refraction and reminding the patient to blink can save time and frustration.
Accommodative dysfunction is amplified with a phoropter, as it restricts peripheral vision, stimulating accommodative lead in non-presbyopic patients.3,4 Don’t skip the binocular balance segment of refraction—blur your patient by +0.75D and gradually walk them back down, confirming an equal result in each eye separately, then together.
This makes for a visually satisfying end result. Put up a red/green screen at the very end of refraction. If the patient reports the green side as bolder and darker, you have over-minused your patient.
Check near vision on every patient and give them +0.50—you would be surprised how many young patients notice a difference in clarity. This may translate to a second pair of glasses for computer use and reading to improve screen-time comfort.
Having a perspective of your patient’s eyes as biological and neurological structures is important for good data AND a good patient experience.

Communication is key to successful refraction

To you, it’s routine. To your patient, a refraction can be a very anxiety-producing experience. They think they’ll "fail," and you’re going to give them coke-bottle glasses if they respond incorrectly.
They think, "...they look the same, but I need to pick one." Just as they are seeing better, you flip the Jackson cross cylinder (JCC) into place, and now it looks like garbage! Just take a look at some common questions regarding refraction on Quora, an online Q&A website below.

Quora patient questions on refraction

  • When taking an eye test, if you can make out a letter but it still looks blurry, should you tell the eye doctor the letter you see or tell them you can’t make it out?
  • How do I properly take an eye exam? I get that you say if you can or can’t see the letter but, let’s say the screen has a “P” on it, and it’s blurry, but I can still somewhat make it out as a “P.” Do I still say the letter?
  • What could cause an optometrist’s electronic testing to show vision is 20/20, yet vision is still extremely blurry?
  • My eye doctor dilated my pupils before the refraction/correction portion of the eye exam. Will this potentially throw off my prescription?
  • When tested using an eye chart, should you read aloud any letter you can vaguely perceive or only the ones you can see comfortably and clearly?

Two tips for better communication with patients about refraction

1. Err on the side of over-explaining.

An explanation of the process may go as follows:
"This apparatus is going to sit in front of your eyes like a big pair of glasses. It’s okay if it looks blurry or not perfectly sharp yet. The starting point is just an estimate of your prescription. Now, I’m going to cover one eye. During this test, I will repeatedly show you two options at a time.
Several of these will be blurry throughout the process; your number one job is to tell me which one looks clearer to you or if they look the same. It's okay if they look equally bad. I can repeat options if need be. If it’s very hard to tell, say 'same.' That tells me just as much. We will achieve the best result at the end."
Even though it may feel like overkill for your established patients, a comprehensive explanation will put the patient at ease.

2. Listen to your patient.

Does there seem to be a question mark at the end of every sentence? Repeat the test instructions. Does the patient respond to “Which is better, 1 or 2?”  with "Ummm…?" You have your answer, move on. Now talk back, "I know this may not be perfectly sharp, but let me know what you notice here." Nuance, baby!
Whether you like it or not, patients will absolutely judge you as a doctor based on your refraction. You may be perfectly managing their intraocular pressure (IOP), catching those tiny microaneurysms on your fundus exam, or even diagnosing a brain tumor!
That is your focus because it matters more to you. However, what matters more to your patient is how they see looking through those little peepholes, and subsequently, their new glasses.

Performing more complex refraction

Let’s address refraction with a chief complaint of vertical diplopia. In this situation, pull out your trial frame and pop in the Rx with a red Maddox lens with the lines running vertically. Next, shine a transilluminator directly in front of them, starting at distance.
The patient should see a horizontal line and a light. If the light is above the line, the eye with the red lens is sitting lower than the eye without the red lens. Prescribe prism accordingly. Even 1PD of vertical prism can be life-changing.5
Multifocal contact lens fit to follow refraction? Check each eye with a red/green screen and balance until each side looks equal or slightly in the red. Often, my patients tell me that they’ve never seen the red/green screen before. When I explain that it results in a more accurate prescription, they are impressed.
Check neural eye dominance quickly by having the patient keep both eyes open in the distance, cranking in the retinoscopy lens (see below) over the right eye and then the left eye—which one is worse? Depending on the phoropter, this lens is typically a +1.50 or a +2.00. If the vision looks worse with the right eye blurred, the right eye is dominant. Alternatively, you can hold a +1.50 trial lens in front of each eye.

Patient satisfaction with refraction

If you want to enjoy five-star patient reviews and increased optical sales, use this one simple trick. If your patient is correctable to 20/20, at the very end of the binocular sphere check, put up multiple rows with the lowest at 20/15.
I like to say something along the lines of, "Humor me, try any letters you can squeak out on the bottom row." Nine times out of 10, they will read the row to you with ease. Then, you get to congratulate them on having “better than perfect” vision with the new prescription.
If you work with a digital phoropter, there is a "money button" at your fingertips. Show the patient their habitual Rx and flip to the new manifest. “Wow, so much better.” This same comparison can be made with a manual phoropter, albeit not as rapidly.

In closing

Not every patient will have a good refraction experience. Your discerning 62-year-old patient with grade 1 nuclear sclerotic (NS) cataract may have read the 20/20 row, but they weren’t very confident.
Circle back at the end of the exam while educating on cataracts. "Now, I know you read me that 20/20 row, but I could hear in your voice that it wasn’t very sharp. That is due to the cataracts, which act as a cloudy filter in your eyes."
This helps the patient feel more at ease, knowing there is an explanation for why their vision isn’t "perfect." This also builds trust in you as their provider.
Now, if you haven’t gotten as fired up about refraction as me after this read, that’s okay. I hope at least I can reawaken you to the fact that we are helping people see clearer and lead happier, more successful lives. And that’s not very vanilla if you ask me.
  1. Woods RL, Colvin CR, Vera-Diaz FA, Peli E. A relationship between tolerance of Blur and personality. Invest Ophthalmol Vis Sci. 2010;51(11):6077. doi:10.1167/iovs.09-5013
  2. Teshigawara T, Meguro A, Mizuki N. Effects of rebamipide on differences in power and axis of corneal astigmatism between two intra-patient keratometric measurements in Dry eyes. Ophthalmol Ther. 2021;10(4):891-904. doi:10.1007/s40123-021-00368-9
  3. García-Guerra CE, Martínez-Roda JA, Ondategui-Parra JC, et al. System for objective assessment of the accommodation response during subjective refraction. Trans Vis Sci Tech. 2023;12(5):22. doi:10.1167/tvst.12.5.22
  4. Casillas EC, Rosenfield M. Comparison of subjective Heterophoria testing with a Phoropter and trial frame. Optom Vis Sci. 2006;83(4):237-241. doi:10.1097/01.opx.0000214316.50270.24
  5. Matheron E, Lê T-T, Yang Q, Kapoula Z. Effects of a two-diopter vertical prism on posture. Neurosci Lett. 2007;423(3):236-240. doi:10.1016/j.neulet.2007.07.016
Veronica Schuver, OD
About Veronica Schuver, OD

Veronica Schuver, OD, is a dedicated optometrist from the small town of Lakewood, NY. She earned her Doctor of Optometry from The Ohio State University.

During her externships, she served veterans at the New Orleans VA hospital. In Athens, GA, she gained extensive experience in ocular disease, low vision, and specialty contact lenses. She is particularly passionate about helping individuals with visual impairments.

Dr. Schuver has been recognized for her work with multiple awards, including the Excellence in Low Vision Award in 2021. She is an active community member and leader, with a history of serving on state and national optometric leadership boards, such as the American Optometric Association. She was awarded the Ohio Optometric Association’s Leader of the Year in 2020.

Veronica Schuver, OD
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