RESPONSIBLE persons in factories, offices and schools are frequently confronted with the question whether existing illumination is inadequate and is causing ocular fatigue. At the present time there are no methods of determining objectively satisfactory illumination.
The purpose of this investigation was to determine whether there were any physiologic tests which could be used to demonstrate the ocular fatigue which occurs during the working day, and which could be used to differentiate good and poor illumination.The problem was approached by testing various ocular functions at the (a) start of, (b) during and (c) at the end of the working day. The various functions tested under numerous conditions were: (1) acuity for far; (2) acuity for near; (3) speed of accommodation from far to near; (4) changes in heterophoria; (5) loss of ability to converge, as measured by the ability to overcome diplopia against increasing diopters of prism,
WEBER RA. OCULAR FATIGUE. Arch Ophthalmol. 1950;43(2):257-264. doi:10.1001/archopht.1950.00910010264008