Influence of Occupational Exposure to Organic Solvent Mixtures on Contrast Sensitivity in Printers

Contrast sensitivity measurement accurately evaluates the sensitivity of all human visual channels, even in a more detailed manner than simple acuity measures can. This is a study of visual contrast sensitivity in a series of subjects occupationally exposed to organic solvents. Contrast sensitivity was measured for 42 printers and 28 age-stratified controls using the Vistech VCTS 6500 chart. The exposed workers distinguished between following three groups of printers: "low exposed," "middle exposed," and "high exposed." Abnormal contrast sensitivity results were recorded for the right eye in 38% of the printers and 11% of the controls and for the left eye in 38% of the printers and 7% of the controls. Especially, we found a reduced contrast sensitivity in all three groups exposed to solvents for both eyes. We conclude that contrast sensitivity is abnormal in workers exposed to organic solvents. The reduced contrast sensitivity in printers seems to be an indicator of visual defects induced in response to organic solvents exposure.