In structural terms, it resembles fusuma, which has a shielding function and serves as a partition, while being different in that it has two contradictory functions, that is, the function of shielding one space from another and that of allowing the passage of outdoor light into an indoor space although it is simpler than fusuma; thus, akari shoji was an epoch-making invention.
建具の構造としては、間仕切りとしての隔ての機能をもつ襖に近く、さらに襖よりも簡素ながら、隔てと採光いう矛盾した機能を併せもつ明かり障子の発明は、画期的なことであった。