I detected my symptoms of aniseikonia some years ago when I was noticing that my new eyeglass prescription was not resulting in a crisp image. While driving, I noticed that if I caused the left and right eye images of the car in front of me to diverge, the left image was noticeably larger. By experimentation, I estimated the difference to be around 10%. In an earlier eye exam, I could see a "lace-like" pattern when looking through my left eye through a tiny hole in an opaque card. I attribute the diagnosed epiretinal membrane to an incident that occurred at a conference -- without any physical symptoms, I suddenly perceived a constricted field of vision surrounded by tiny points of light. My ophthalmologist explained the process of epiretinal membrane (I believe I was actually seeing the cellular structure as “lace” in the eye exam, since it was explained that the tiny points of light were blood cells -- which disappeared over the course of a few days), but I did not perceive the disparate image size at the time. I noticed that the disparity was a substantial annoyance, and made vision uncomfortable, particularly in my work in the legal field. I must read a great deal and also be able to see what is going on around me in a courtroom setting.
When I discussed the difference in image size, my ophthalmologist named the symptom “aniseikonia” but had no suggested response.
I researched the issue on the internet, and came upon the Aniseikonia Inspector, and corresponded with its creator, Gerard de Wit. He sent increasingly improved versions of the software, which I used to verify and quantify my aniseikonia and, eventually to give my ophthalmologist specifications for corrective lenses. She and Gerard collaborated, she used a version of the program, had her optician spouse grind some test lenses to test the available degree of magnification, and with those I was able to determine the optimum correction available with glass lenses (I have rejected contacts, which might achieve a higher degree of correction, and I’m hopeless with plastic lenses).
The result was a pair of glasses that substantially diminishes the disparity in image size and achieves a fully acceptable reading and viewing comfort at work and otherwise. Gerard's service and the Aniseikonia Inspector provided me and my ophthalmologist a solution to my vision problem that as far as I can tell was largely unknown in the field, and I am grateful for the improvement.