VEP (Visual Evoked Potential) STUDY AND CONTRAST SENSITIVITY TESTING USING NVGS: STANDARD LENSES VS. ABERROMETRIC LENSES

INTRODUCTION The author's have conducted a preliminary study that compares standard lenses with aberrometric lenses using night vision goggles (NVGs). In addition, the au­thors then evaluated the VEP exam at differing contrast levels, and, in conclusion, investigated contrast sensitiv­ity in binocular vision between the two different types of lenses. The test subjects are flight crew personnel who wear standard glasses to correct refraction errors. METHODS Ten male test subjects underwent a standard ophthal­mologic eye examination with refraction detection that was followed up with an evaluation using the i-Profiler Zeiss for auto refractometric, keratometric, aberromet­ric e topografic testing. While wearing NVGs with stand­ard glasses (controlled) and NVGs with glasses having  aberrometric lenses, the test subjects were evaluated with the VEP exam with a bar stimulus pattern show­ing 4 different levels of contrast (4%, 11%, 26%, 53%). Subsequently, they underwent testing for sensitivity to contrast in binocular vision using the Zeiss Vision Test. TEST RESULTS From the analysis of the VEP test, which was conduct­ed with NVGs having both standard lenses and aber­rometric lenses, the authors noted a trend of improve­ment in the variation of the amplitude of wave N75 that showed a statistically significant result at 26% percent of contrast (p < 0, 05), When utilizing NVGs with the two different types of lenses, the results improved from with­in 3 c/deg concerning contrast sensitivity in binocular vision with aberrometric lenses. DISCUSSION Improved contrast sensitivity is achievable with aber­rometric lenses given the combination of three factors: the technologically advanced precision of the equip­ment used for objective refraction; the wavefront aber- rometry analysis; and, the perfect centralization of the lenses. Together, these factors take into account the actual needs of the patient and provide a personalized visual profile. When visual acuity is equal between the standard lenses and the aberrometric lenses, the aber­rometric lenses are able to improve contrast sensitivity.