The screenings that are done at schools or at the pediatrician's office are usually very basic, and a lot of the essential tests that an optometrist performs are not done during a screening. Without any assessment of ocular alignment, binocular function, accommodation and convergence, these screenings are providing no info as to how a child is performing with reading and tracking. I have seen children "pass" their school screening, but fail their comprehensive eye exam. And vice versa. One of my favorite things about being an optometrist is pediatrics, as it is incredible how much a child's academics, attention, and headaches can start to improve once the proper glasses Rx is prescribed, if necessary.