The ability to see in stereo. What does that mean? Basically, stereo-vision is the ability to see depth in our visual space. That is, the ability to tell that space exists between objects in the environment.åÊ In essence stereo vision is your 3-D vision. It is the abilityåÊto judge depth because you actuallyåÊsee depth.åÊThis is accomplished through normal binocular (two-eyed) vision.
Most of us relate to this as we see 3-D pictures or 3-D movies. However, it is much more than that…stereopsis provides a quality of vision that is much like color vision. To those who are color blind, the ability to “see” exists, but the color deficient individual lacks a quality of vision that can only be described as a phenomenon of see the world with a quality of color perception. The world of color can not beåÊeasily put into words. The same is true with stereo vision. Until you see it you don’t know what you are missing. But, to be sure the stereo-blind are missing a lot!
Stereo blindness occurs whenåÊthe two eyes do not work together in a normal way. If a person has only one eye they are truly stereo-blind with no hope of gaining stereopsis. However, most patients who are stereo blind have two eyes, but just lack the ability to use the two eyes together in a normal way. Examples of this are those individuals with strabismus (crossed or turned eyes), amblyopia ( lazy eye) and another moreåÊcommon condition, non-strabismic binocular vision dysfunction. This later condition is where the individual has some ability to use their eyes together but, they just do it poorly.
Unlike color blindness, the good news is stereo blindness in the patient with a binocular vision problem, is usually curable with office based vision therapy. The other good news is for those who have a non-strabismic binocular problem the treatment time is much shorter!
To hear more about stereo blindness, the followingåÊPodcasts may be of interest.
How can you tell ifåÊ your child has stereo blindness? One good way is to see if they can see the depth or “float” of the images in the 3-D movie Avatar (or other kid friendly 3-D movies). If a child says it just looks “smeary”or “blurry like” and not really “coming out” you should åÊsuspect a problemåÊwith theiråÊbinocular vision. Contact your family eye care provider for an appointment to check their vision including their “stereo-vision”! If there is a problem, make sure that your doctor will be able to prescribe treatment or make a referral to a specialist in treating binocular vision problems with office-based vision therapy. If you need assistance finding a doctor who can treat stereo blindness go to the College of Optometrists in Vision Development website at www.covd.org and click on the Doctor Finder. There you should look for those Doctors who are Board Certified Fellows.
Dan L. Fortenbacher, O.D.,FCOVD