Evaluation of the Arjun’s Royal Air Force rule device as a new tool for assessing near point of convergence and near point of accommodation

Dear Editor, The article titled “Evaluation of the Arjun’s Royal Air Force Rule device as a new tool for assessing near point of convergence and near point of accommodation” by Varshney et al. was very interesting and thought provoking. Integrating technology into binocular vision assessment will improve predictability in such evaluations which otherwise depend largely on subjective assessment. But we made a few observations that we thought would bring to your attention. The authors say that participants aged 10 to 40 years were recruited for the study. The inclusion criteria do not mention the near vision parameters since it can vary especially in 40-year-old patients. It is interesting to note that they have excluded presbyopia. It is also noted that in the inclusion criteria “mild” and “severe” refractive errors are mentioned, which are not clearly defined. Another observation was regarding the control instruments. It says an “auto refractometer” was used to ensure that all participants achieved corrected vision to 6/6 before near point of accommodation (NPA) and near point of convergence (NPC) assessment. We would like to ask the authors if cycloplegic refraction was conducted for children who participated in the study or if their refractive correction was done only based on auto refractometer and trial of glass. This is very important in the case of children, who might be having latent hypermetropia who might be missed if a cycloplegic refraction and post mydriatic test is not conducted.1 Finally, it is not clearly mentioned what the patient sees, while his/her NPA or NPC is being measured with Arjun's royal air force (ARAF). The subjective perception needs clarification since it is a crucial element in deciding the efficacy of the instrument. The type of target is an important factor in NPC evaluation since accommodative targets result in a more proximal NPC and underestimate the NPC values.2 Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest to declare.