No Near-Reading Charts Met International Standards in Multi-Product Study

ISO standards for near-reading charts include such criteria as 0.00logRAD text size, a minimum text contrast of 85% and line spacing no greater than 1.5. The University of Canberra team developed the above chart and say it complies with guidelines. Serif and sans-serif options are available. Find the link in this article to download a copy. Photo: Murphy TI, et al. Ophthalmic Physiol Opt. June 11, 2026 (per Creative Commons 4.0). Click image to enlarge. A recent study from Ophthalmic and Physiological Optics found that commercial near visual acuity charts varied widely in text size but that none fully met international standards, potentially affecting the accuracy of near-vision diagnoses and optometrists’ ability to monitor patient vision.Researchers from University of Canberra in Australia evaluated 19 near-reading acuity charts commonly used in community optometry clinics, including commercially available charts and those provided by ophthalmic device manufacturers, explaining that they assessed the charts “at 600 dots per inch” to determine how closely they complied with the requirements outlined by the International Organization for Standardization (ISO), a global organization that develops universal standards for a variety of products and services. You can download the new chart developed by this research team here.After their assessment, the authors reported that all charts “met the line spacing requirements and the minimum required contrast level,” but that “some charts were printed on laminated or satin plastic, which does not meet the standard of using a matte surface.” They noted that only one chart had text sizes that were entirely within ISO tolerance limits. Twelve charts used serif fonts and seven used sans-serif fonts, with serif charts generally having text that was smaller than required. Their average deviation from the standard size was -9.63%, while sans-serif charts averaged +4.96% from expected sizes. The researchers also found labeling inconsistencies on several charts, including the use of logMAR despite it primarily being “mainly used for distance letter acuity charts” and inconsistencies in N-size and Snellen designations. Only four charts included the required 0.00 logRAD line specified by the standard.The authors concluded that variability among reading charts could lead to eye conditions going unnoticed or getting misdiagnosed, as well as exaggerating subtle changes in visual function, particularly when different charts are used at different clinics. They recommended in their paper that clinicians use the same chart consistently when monitoring disease progression and “be cautious when comparing visual acuity results using different reading charts.” Additionally, in response to the findings, the researchers proposed an alternative self-created reading chart that they designed to meet all current standards.Click here for the journal source. Murphy TI, Chen J, Leung M. How accurate are our near reading charts? An assessment of 19 charts against ISO standards. Ophthalmic Physiol Opt. June 11, 2026. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.