Are Glasses A Substitute for Vision Therapy?

Optometric vision therapy (OVT) involves a significant commitment.  There is a commitment of time in order to travel back and forth weekly to the optometrist’s office.  There is of course a certain expense involved in order to achieve the best outcome.  Staff must be trained well in helping to provide this specialty service, and state of the art practices invest in advanced technologies.  Not all insurance carriers reimburse the patient for vision therapy.  It would therefore be very attractive if a simple pair of glasses could take the place of the commitment required to succeed through vision therapy.  After all, who wouldn’t hope that a simple crutch, brace or appliance could substitute for the need to undertake months if not years of physical, occupational or speech therapy?  Much as the answer is there is no magic bullet for any other form of therapy, there are no lenses or prisms that can substitute for what can be accomplished through office based optometric vision therapy.

Here is an interesting exchange from the forum  The question posed is:

“I am looking for an eye Dr. that is experienced in treating dyslexia. A couple of pple recommended a top Dr. named Dr. Clyde Alexander from UK. Does anyone have anything to say about him???”

The first comment offered in reply is:

“My DH has prism glasses – AFAIK they aren’t difficult to make. He has had worlds of improvement since he got them about 4 months ago from a local neuro-opthamologist.”

So what do prism glasses look like?  In the amount usually prescribed for children who are having developmental or learning problems, or other types of special needs, they look like any other pair of glasses.  They can be combined with any prescription lens power, and can incorporate any colored tint or anti-glare lens coating or treatment.  The most common use of prism is base-in reading glasses for convergence insufficiency (CI).  Is there any research about the effectiveness of these glasses?  Absolutely, and it does not support the magic bullet theory.  In 2005 the CITT Investigator group completed a randomized clinical trial comparing the effectiveness of base-in prism reading glasses and placebo reading glasses. The results, published in the British Journal of Ophthalmology, showed that the base-in prism glasses were no more effective than placebo glasses. Their conclusion was that base-in prism reading glasses is not an effective treatment for children with symptomatic CI.

The image above, from the site HowStuffWorks, helps demonstrate what lenses and prisms do.  Every prism has a thin part called the apex, and a thick part called the base.  Prisms shift the visual space in the direction of its apex or away from its base.  It’s good to keep in mind that every lens prescription has prism properties in it, depending on which part of the lens you’re looking through.  For a minus lens, used to provide clarity to those who are nearsighted, the thick part or base is at the outer edge.  For a plus lens, used to ease focusing effort for those who are relatively farsighted, the thick part of base is at the center of the lens.

Let’s return to the comments from  If a parent obtains a pair of prism glasses and they provide a world of improvement, that is wonderful.  I’m all in favor of any intervention that can provide help to children with visual dyslexia, or with any special needs for that matter.  In many cases a lens or prism prescription can be a very good adjunct or complement to making changes through vision therapy.  A lens or prism prescription can be a valuable tool that helps a patient internalize changes made through vision therapy.  In some instances a lens or prism prescription is used to help maintain gains through therapy, guiding growth and development almost like a retainer used after a child has had braces.  The key point here is that no “special pair of glasses” incorporating lenses, prisms or tints has ever proven to be an effective substitute for office-based optometric vision therapy.



15 thoughts on “Are Glasses A Substitute for Vision Therapy?

  1. There are numerous “political” and “business” reasons for the rejection of therapy of any kind in care of the patient. One is professional turf. Another is vested interest of those who supply pills, eyewear, drops, surgery, etc. There are philosophical differences. Put simply “If it ain’t broke don’t fix it,” or if the pain of discomfort is alleviated (through the use of symptom suppression) than that quick fix is all that is needed to satisfy the doctor’s “customer.” In addition, it is easier for the third party carriers to use actuarial tables to compute risks for them than to care about the needs of their clients. Society is bombarded with advertising for quick fixes. It is only after these approaches to care result in no help, permanent dependency, or adverse side effects that they finally, after much undue expense and “trauma” end up with the right kind of therapist.

    • Very good points. I began reading an inspiring book this morning by a psychiatrist, Dr. Dale Archer, who notes the over-reliance on quick fix pills rather than therapy in his field, and how that’s compromised his field. The public is misled by those pandering quick fix cures. While there are many economic and professional turf forces that come to bear, there simply is no shortcut to therapy. Much as Archer underscores that he is not opposed to medication, we are certainly not opposed to the use of lenses and prisms – just keeping what they do in perspective.

  2. Len,
    The person in question that got better with prism, did not mention what type of prism lenses. Base in, base out, base up, base down, yoked, etc… Maybe this person had a slight vertical deviation causing them to skip words and not move their eyes properly together. Maybe they had some other condition that prisms are excellent at improving.
    Prisms do many things to the light as we perceive it and it is what the person does with prism is that is the effect. Each person individually reacts to the slant, tilt, magnification, minification, VOR changes, and shift of prism differently. Some prism helps patients process this information, some prism makes it more difficult to process. There are many, many considerations when prescribing prism and I find that those that don’t prescribe prism on a regular basis tend to over do it and really don’t do it well. Those of us that prescribe it daily know that without therapy prism may work for a while, but therapy improves functioning continually.

    Jason Clopton, OD, FCOVD

    • Well said, Jason. Certainly prism can be very straightforward as in the case you mention for uncompensated vertical deviation, or even yoked prism to put a person in a greater zone of fusion. What I’m referring to is different. Several of us in the NJ/NY area have encountered lately that the gentleman in England referenced in the discussion has set himself up as a guru of sorts, solving a myriad of problems – but principally dyslexia – with +0.50/low base-in and a proprietary tint. I have no knowledge of the individual, but I have checked out an Rx that one of these patients brought back. It is always of concern when someone claims in essence to have a “cure lens” that can only be obtained through his lab or auspices. It is also of concern when these “special glasses” are touted as an effective alternative to office based vision therapy.

    • Lenses are used in early developmental stages for guidance in development. They are not permanent. They do not compensate for refractive error.

  3. How are prism lenses different than binary lenses? My daughter’s theraputic optometrist prescribed binary lenses to correct her double vision and amblyopia. She now sees singularly with dimension. This was just the first step toward her recovery. Currently she is focused on physical therapy with vision therapy on the horizon.

      • No not bifocal. At our follow up I called her prescription a “prism lens” and he corrected me by referring to it as “binary”. And I’m referencing my notes, I was told binary lenses work “subcortical interfacing or body maps”. Just trying to deepen my understanding. I am completely pleased with our progress so far.

    • Becky, who is the Dr. who prescribed your daughter’s the binary lenses? Our Dr. just passed away, and my son uses binary lenses. We are looking into next steps for him. He has strabismus, which is intermittent. The lenses correct it, but is proprioceptively induced, so we have done other therapies and have to adjust as he grows.

      • We saw Dr. Collier. I’m so sad to hear of his passing. As with your family, I’m sure, his treatment improved my daughter’s well being tremendously, and for that I am eternally grateful. In addition to Dr. Shidlofsky, Dr. Stendig in Garland also is familiar with Dr. Collier’s treatments. His website is When deciding upon a doctor, I interviewed both practices and learned that Dr. Stendig and Dr. Collier at one time considered forming a partnership.

  4. Great to hear you’ve been making good progress. I think I’ve found the answer here: Dr. Wylie notes: A yoked prism spectacle prescription helps synchronize communication to allow more efficient and accurate information processing. “A variation of prism design known as binary optics that also change the phase of light have been used in nautical lighthouses, holographs, spectrophotometers and its optical principles provide for the clear picture on a flat screen TV.” So binary seems to be someone’s proprietary description of yoked prisms.

    • Hi Len, I first heard the term “binary” lens in a seminar with Dr. Richard Collier from Dallas, TX. Dr. Collier doesn’t have much information about them on his website, but Dr. Wylie was also in that seminar. From my understanding, they are used as a description of “microprism” lenses.

  5. Thanks, Robin. Dr. Collier is our optometrist. I’m glad to know he is out there presenting his information to others. As I mentioned before I am a lay person helping to advocate for learning disabilities as a result of vision problems. His knowledge helped to improve my 7 year old daughter’s vision, got us started with an intense physical therapy program to integrate reflexes, and at our next follow up, probably a vision therapy program. Her changes have been remarkable and I anticipate future academic success. I am so grateful for everyone who helps people overcome all kinds of vision problems!

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