Refractive errors, especially when in significant amounts, have serious effect on academic performance. I will remind you the importance of convergence insufficiency. In presence of convergence insufficiency, very small amounts of myopia, astigmatism, or imbalance between eyes cause considerable asthenopia. According to my experience, a student with 1 or 2 diopters of myopia may have no discomfort during reading if he or she doesnt' have convergence insufficiency.
Hi, Muhammed. You might want to look at Kulp, et al
Attention and Visual Motor Integration in Young Children with Uncorrected Hyperopia Optom Vis Sci 2017; Vol 94(10) and note it's from the Vision in Preschoolers-hyperopia study group. Same group came out with
Article Uncorrected Hyperopia and Preschool Early Literacy
Those look at higher levels of hyperopia. My area of clinical research has been on non-strabismic suppression and its effect on reading. What I found in the group of suppressors I had seen, who generally complain of reading problems, is that the refractive data are very normal. In fact, I superimposed the data from a 1985 paper from Helveston, et al (saying that refractive error is not related to academic problems), on my data from suppressors who do have problems (specifically reading) and they are a close match. So, the bottom line from my perspective is that hyperopia, perhaps even small amounts, can be a problem or part of the problem, but stability of central sensation is a key. In my view. And it looks like there is a group looking at hyperopia.