Effects of atropine/2-PAM chloride, heat, and chemical protective clothing on visual performance

Visual acuity, phoria, stereopsis, and contrast sensitivity were assessed over 6 h of continued exposure to combinations of atropine (2 mg) and 2-PAM chloride (600 mg), severe heat/humidity (95 degrees F (35 degrees C); 60% RH), and wearing either the U.S. Army battle dress uniform (BDU) or the BDU and the impermeable chemical protective clothing (MOPP-IV). Subjects were able to complete all 6 h of testing under severe heat when wearing BDU's, but only lasted 2 h under the same severe heat when wearing MOPP-IV. Acuity and phoria were significantly impaired by the drug in the BDU conditions. Acuity, phoria and stereopsis were all significantly impaired by heat, drug and continued exposure under MOPP-IV. Acuity was significantly impaired by drug even during the first 2 h of heat exposure in MOPP-IV. Contrast sensitivity was impaired mainly by continued heat exposure in MOPP-IV.