Aniseikonia can be caused by any asymmetric changes in the optical components of the eyes that results in a difference in retinal image size. Possible causes may include unequal prescription between the two eyes, cataract surgery, intraocular lens implant, refractive surgery, retinal detachment, and macular degeneration.
Aniseikonia is very difficult to diagnose. Many of the classical instruments that measure aniseikonia are not manufactured any more. Only a few eye clinics today are equipped with the expertise and instrumentation to diagnose and treat aniseikonia.
As many of 10-15% of the population may have some aniseikonia; not everyone becomes symptomatic from it. It becomes clinically significant (about 4% of the population based on the Dartsmouth Study) usually if (1) it is of late-onset, i.e. the brain has a hard time readjusting to the size difference, (2) the patient is very sensitive to small visual changes, and/or (3) the patient's work of life-style places great demand on the visual system.
Yes. At our clinic, we utilized a state-of-the-art aniseikonia test that measures aniseikonia to the nearest 1%.
Iseikonic lenses are custom-designed lenses that alter the magnification in one or both eyes by changing several lens parameters: front curvature, center thickness, vertex distance, and/or lens material. The perceptual disturbances caused by the image size difference between the two eyes are relieved by either magnification of the eye seeing through the smaller image and/or minification of the eye seeing through the larger image.
Yes. Iseikonic lenses, contact lenses, vision therapy, occlusion therapy, or a combination are possible treatment options . Only a comprehensive evaluation can confirm the diagnosis of aniseikonia and rule out other similar visual disorders before the best recommendations can be made.
