Saccadic eye movements in normal children from 8 to 15 years of age: a developmental study of visuospatial attention.

Evans et al. (1994) mapped how three parts of visual attention grow in typical kids. They tracked fast eye jumps, called saccades, in children aged 8 to 15. The team used simple computer tasks to see how quick, accurate, and large the jumps were.

All three eye-jump skills got better with age, but each on its own speed. One skill zoomed ahead early, another stayed flat, and the third inched up slowly. The data give clear age-based norms for each piece of attention.

Chien et al. (2016) extends these norms to teens with autism. They show the same age range, but the ASD group lags behind the curve you see here. Tassé et al. (2013) use the same trajectory method for kids with Williams or Down syndrome; their visuospatial memory grows at the same slow pace, not faster or slower. Klin (2025) pushes the eye-tracking idea even younger, arguing that FDA-cleared tools can spot autism in babies before these norms start. The 1994 study still stands as the clean baseline they all compare against.

You now have a ruler. If a 12-year-old’s saccades match the 8-year-old norm, flag it. Pair the ruler with later work like Chien et al. (2016) to see if the gap points to ASD, ID, or another issue. Use the three separate curves to decide which part of attention to target in your intervention plan.