Tricks to taking the “What’s Better One-Or-Two” Eye Test

Question: Which of these is the most anxiety producing of medical procedures? (a) Shots, (b) tongue depressor, (c) having a cavity filled or (d) answering the question “what’s better, one or two?” at the eye doctor. While most people would choose the first 3, you’d be amazed at the level of anxiety I witness when my patients are asked to distinguish between two slightly different images during the eye exam/eyeglass test called “refraction“.  I see all ranges of reaction, from those who are confident and decisive to those who answer a different question than I ask. “What’s better one or two?” Answer: “Well, one is brighter than two, or two seems slightly greener than one.” Why is this test so anxiety producing and what do patients need to know about answering these questions so they can assist their doctor in finding the right eyeglass or contact lens prescription instead of hindering their efforts?

I think the answer lies in the way people interpret the question. The doctor, in asking you to discern between two similar images, is asking a literal question, meant to be taken literally. By not specifically answering the question based on “clarity” and inputting additional information regarding color, position or something else, the patient muddies the water for the doctor. Remember, the optometrist likely performs this test between 5000 and 10000 times a year, so they get a “feel” for things and know when their questions are being answered properly. Sometimes it isn’t fair to ask the patient what image is “clearer” as there can be different interpretations of clarity – one person may think darker letters are clearer, while another might think letters on a brighter background are clearer. To eliminate the subjectivity within this question, I frequently ask my patients “which image do you prefer? 1 or 2”. This phrasing of the question increases the likelihood that the image choosen is indeed favored by the patient, increasing the likelihood that it is indeed the “clearer” image.

People also often make an assumption at the beginning of the test that throws them and possibly the doctor off at the beginning. That assumption is that when the doctor asks which choice is clearer, they are actually seeking to clear the patients vision by moving the “clearer” lens infront of their vision. Frequently the “whats better one or two test” is done in the “blur” on purpose – a doctor might be asking you which image is clearer but actually be seeking the blurrier image. There may be several reasons the doctor does this. It may be because there are some inconsistencies in your answers, so the doctor needs to go backwards or start from scratch, gradually clearing your vision. It may be because the doctor is using a technique known as “fogging”, where more consistent results are gained testing in blur for people with overly active focusing systems. The worst thing you can do during the test is try to outwit the doctor, assume you know what answers he/she is looking for or elaborate your answer with other information you feel might be pertinent to the doctors data collection – it is likely you will only negatively alter the results causing the refraction to need to be repeated and increasing the risk of not being able to adapt to your glasses or contact lens Rx.

Sometimes I will ask the question “what’s better one or two?” and the patient will start reading the letters, seemingly ignoring the fact that I am there answering the question at all.  Othertimes, I will say “what’s better one or . . ” and before I even show them the second option they choose one without even having seen the second option.  This tells me that they aren’t paying attention, so I will stop the test and take the time to politely explain how it works.  Sometimes I will notice them having trouble answering a question and when I glance to the side I see them squinting to see better.  That is a sure way to end up with glasses that they have to  squint through to see, and a sure way to end up back in the chair a week later after receiving glasses they can’t see through, thinking that doctors error caused their lenses to be incorrect.

Some tips for test takers (1) your forehead should be gently resting on the forehead rest and your cheeks shouldn’t be touching the body of the “phoropter” (the machine in which you perform the test) (2) Do not squint to see. (3) If you are not lined up properly; ie if you can’t see the chart directly infront of you tell the doctor so he can proceed to align the phoropter correctly. (4) Don’t close one eye or the other while behind the phoropter. The doctor can control occluding your vision by closing one or the other of the eye holes, and when you purposefully close one eye you can’t help but squint with the other because the closure system of the eyes is binocular; ie they want to close together.  (5) If you worked out or are hot or sweaty, you may fog up the lens in the device resulting in difficulty distinguishing between two choices.  Make your doctor aware of this.  (6) If you have always had one eye that you can’t see out of, or that is particularly worse than the other eye, tell the doctor before he/she starts the test. (7) If you have particular anxiety about testing in this device, request the doctor perform a “trial frame refraction” – this is a way of performing the same test that might be less anxiety producing for you.

I hope you find this information helpful.  For more information on eye and vision care issues visit my practice website

You can also follow my posts on Twitter @EyeInfo

Don’t forget to join the EyeHealth Information Network on Facebook.  By increasing the groups popularity I am able to provide free eyecare to people in need.  No donations are necessary; it is a great way to exchange health care with no exchange of money and give back to the community as well.


Dr. Alan Glazier

Copyright 2010 –

Courtesy of the Doctors at Shady Grove Eye and Vision Care; Optometrists, Ophthalmologists and Opticians working together to help you see better.  Serving the Rockville, Potomac and Gaithersburg Maryland suburbs of Washington, DC for over 40 years. For more information visit or call (301) 670-1212

Follow us on Twitter @EyeInfo


4 Responses

  1. […] Tricks to taking the “What's Better One-Or-Two” Eye Test … […]

  2. This is a good piece of content, I was wondering if I could use this piece of writing on my website, I will link it back to your website though. If this is a problem please let me know and I will take it down right away.

  3. I enjoyed your technical version describing what we do daily. I tend to write’off the cuff’ as the thoughts arrive between patients

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: