Optometry & Visual Performance 162 Volume 14 | Issue 2 | June 2026 determine what our report letters mean. Besides, a lot of electronic health records contain drop-downs in the nVA fields for reduced Snellen. RS just makes so much sense.” “I hear you saying, Rochelle,” Professor McIver began, “that the convenience and emotional comfort of using RS makes it the best choice for you. I get that, and many practitioners prefer it too for just those reasons. Also, people outside optometry, such as nurses, teachers, OTs, and primary care physicians, have a warm feeling for thinking they know what RS means. But what actually does RS mean? It only has psychometric validity if the chart is held at the prescribed distance, but in standardized recording of RS, there is no place to note the working distance. This is a trap into which many people fall: not ensuring the working distance is the one specified on the near VA chart. Sadly, I see this happening more often than not. Let me give you an example: I observed a post-op tech who was assigned to give a one-day cataract patient her acuity test with a near chart. The tech removed the surgical pressure patch, handed the patient the near VA chart, telling her to hold the chart where she saw it best, and read the lowest line she could. Well, the patient proceeded to hold the chart at about 20 cm and read off the 20/25 line. The tech then recorded 20/25 on the patient’s chart. It was at this point that I interrupted and told the tech that was not the correct acuity to record, and she rebutted with that was how the surgeon taught her. Clearly, neither understood nVA. I sensed a teachable moment and asked the tech to read the top of the chart where it was written, ‘To be used at 16 inches or 40 cm.’ The ensuing corrected working distance yielded a nVA of 20/50 that made much more sense given the state of dry maculopathy the patient had in that eye.” “Oh, I see what you are saying,” Rochelle said thoughtfully, “Unless I record the working distance with RS, no one could know the actual nVA. I see now that it is a potentially misleading nomenclature if we are using RS without recording working distance to take a baseline acuity or follow up on disease progression.” “You got it!” exclaimed Professor McIver. “RS is only valid if it is recorded with the actual working distance. If it is not recorded that way, the value of the RS should be discounted. There is no way of knowing the true VA unless we know actual working distance and actual size of the optotype. So, to summarize, RS is a goodnews, bad-news situation, where the good news is that we have a high comfort level using it, but the bad news is that RS is a trap waiting to happen if we do not record working distance with it.” “Now, on to the next nVA system of nomenclature, the point system, also known as ‘n’. Ahn, would you take the advocate role, please?” asked Professor McIver. “Certainly, and thanks for assigning me this one,” Ahn commenced. “The point system originated centuries ago, when physical type sets on printing presses were used. That means it has a long history of being used in and by printing presses, books, librarians, and publishers. A single point is 1/72”, so it is an actual size, not like RS, where we do not know the actual size or working distance. Interestingly, in word processors, the font size is roughly equivalent to ‘n’, so in communications with teachers of the visually impaired or librarians, it would not be far off to equate font and point size.” “Very good, Ahn,” Professor McIver interjected. “It is important to have an actual size when dealing with true VA, but that is only half the equation. What about the actual working distance, such as when someone records nVA as 10 point?” “Not a problem; we just say, for example: 10 pt at 40 cm,” Ahn proudly proclaimed. Now we have an actual working distance and an actual size. That makes the ‘n’ system better than RS, right?” “Indeed, it does, Ahn,” Professor McIver said, “but how does one record that to make comparison with dVA easy and quick, especially when you mix metric and imperial systems?” “Oh,” Ahn pondered. “I see what you mean. Creating a Snellen fraction would be awkward at best.” “Not to worry,” Professor McIver assured him. “At least with an actual working distance and actual an size of the letter, we can eventually extrapolate a psychometrically valid nVA. For now, know that any ‘n’ measurement must also be recorded with the working distance. “On to the J-system,” Professor McIver said. “Jesse Johnson, I hear you are an advocate of using the J-system for nVA. Would you please explain to the group why you find it so compelling?” “I got this,” Jesse eagerly exclaimed, “but just call me J.J., please. “Jaeger has been used all over the world since the mid-19th century. Developed in 1867, originally a set of paragraphs of variable size. Nowadays, it is usually seen on a near-point card with single letters. All the surgeons I know use it, and electronic health records frequently have it in dropdown menus. That gives J-system the advantages of widespread use over many years.” “Nicely stated, J.J.” Professor McIver complimented. “It is indeed a commonly used nVA system that has been around a very long time. Before I begin my
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