Abstract
Purpose: :
To evaluate differences in various aspects of the visual perception using protective optic filters for welding tasks. Two interposed filters are compared: a conventional protective optical filter and a new protective optical filter with selective absorption designed by University Complutense of Madrid (UCM).
Methods: :
36 people of working-age were included in a cross-sectional prospective observational study. The study was carried out in photopic conditions, and in near and binocular vision: Visual Acuity by Runge Pocket Near Vision Card Test (VA); Contrast Sensitivity by VCTS Test (CS); Stereopsis by Titmus Test (TIT), Color Discrimination by Farnsworth-Munsell Test D-28 (F28). Three conditions were set: a) without optical filters interposition; b) with an interposition of conventional protective optical filter for welding (shade 2.5); and c) with an interposition of a novel protective optical filter of selective absorbance that fully blocks the short wavelength light and minimally attenuates the remaining bands of the visible spectrum.
Results: :
Every aspect of visual perception evaluated diminished 50-70% with the conventional protective optical filters. On the other hand, UCM optical filters provoked a low-level decrease in visual perception (15-35%). Without optic filter: VA=0.1±0.22logMAR, TIT=97±95seconds of arc, F28 errors=5±4, CS1.5cpg=4.89±0.32,CS3cpg=5.42±0.77,CS6cpg=4.17±1.3,CS12cpg=3.44±1.87,CS18cpg=2.81±2.29. Results with conventional optical filter were: VA=0.49±0.06logMAR,TIT=279±531seconds of arc,F28errors=17±3,CS1.5cpg=2.58±1.36,CS3cpg=2.47±1.56,CS6cpg=1.5±1.18,CS12cpg=0.58±0.81,CS18cpg=0.19±0.52. With the new optic filter: VA=0.13±0.22logMAR,TIT=89±78seconds of arc,F28 errors=6±4,CS1.5cpg=4.81±0.47,CS3cpg=5.08±1,CS6cpg=3.58±1.38,CS12cpg=2.94±1.91,CS18cpg=1.92±1.71.
Conclusions: :
Conventional optical filters resulted in drastically diminished visual function. The novel and attenuator optical filter of selective absorbance blocked the short wavelength of light, maintaining the transmission of the medium and long wavelength. UCM optical filter preserved or minimally diminish the visual function, allowing a suitable visibility and also maintaining an appropriate level of protection against phototoxic damage. Thus, the referred novel protective optic filters are considered a full protective system for welding tasks and currently are undergoing a process of standardization.
Keywords: perception • neuroprotection • radiation damage: light/UV