Accommodative rock: a normative study on a grade school population

A general vision screening was performed on 566 1st and 4th grade school children from which the accommodative rock test was normed. The procedure consisted of a + 2.00D lens flipper, recording the number of lens flips for a one minute testing. This included an intermediate count taken after the first 30 seconds and a final total count after 60 seconds. A significant difference of the normative means was found between the 1st and 4th grade population. No significant difference was found within each population between those who passed and those who failed the general screening, or between the first 30 seconds and the final 30 seconds of testing