• Does being in dark places for an extended period of time increase the IOP (intraocular pressure) because the eyes would be constantly dilated?


    Question:

    Does being in dark places for an extended period of time increase the IOP (intraocular pressure) because the eyes would be constantly dilated?


    Answer:

    There is no known association between dark room–induced dilation and elevated IOP in normal eyes with open angles. However, in narrow angle eyes (eyes with irises pushed too far forward, causing IOP to rise), which have not been previously treated, darkness–induced dilation could certainly invoke an angle closure attack, which would be characterized with very elevated IOP.