Birth order is thought to affect everything from a child’s personality to IQ. Now ICO professors Drs. Christine Allison and Darrell Schlange, OD ’64 have concluded that birth order can also affect vision. They’ve found, in the first known study of its kind, that first-born children tend to have better eye movement skills, which suggest a higher reading readiness prior to entering kindergarten. They presented the findings at the American Academy of Optometry’s annual meeting in Denver last November.
“Our research demonstrates that first or only children enter kindergarten with better visual function,” says Dr. Allison.
“This may result in early school success and earlier reading when compared to children later in the birth order,” says Dr. Schlange.
The results suggest that coloring, drawing, putting together puzzles, solving mazes and working in activity books—activities first-born children are routinely encouraged to perform before entering kindergarten—may lead to better eye movement skills at that age.
The study also looked at changes in visual function and found that 30 percent of students had developed vision problems between kindergarten and third grade. Not one of these students had been diagnosed with visual problems during their pre-kindergarten exams.
“This is a trend we expect to see more often,” says Dr. Allison. “Students today use technology, such as computers, hand-held devices and tablets, in the course of their school day, but we are finding that those devices put undue stress on visual systems while they are still developing.”
Drs. Allison and Schlange are careful to point out that increased screen time is only one variable at work; others include changes to kindergarten curriculum, less time for recess and recreation, and increased demands on students’ visual attention. Nevertheless, they recommend monitoring children’s use of backlit screens, even for educational purposes, to give kids’ visual systems a better chance to develop appropriately.
The findings are part of a longitudinal study that followed 128 students with similar socioeconomic backgrounds from kindergarten to third grade. Students at a Chicago parochial school were given comprehensive eye examinations including eye-movement tests and full ocular health evaluations the summer before they entered kindergarten. A subset of the same group was examined again the summer prior to entering third grade.
“We believe more research is needed to further examine the rapid changes in our children’s visual functions,” says Dr. Schlange. “Ours was a small sample size but we saw big changes.”
Changes in visual function can have an effect on academic performance. “Reading in third grade historically moves away from the ‘learning to read’ model and becomes more focused on ‘reading to learn,’ which is why it is so important to diagnose any new or worsening vision problems before they cause academic difficulties,” says Dr. Allison.