An assessment of the ANV 20/20 focusing aid for night vision devices.

Night vision goggles (NVGs) are becoming an increasingly important tool in military aviation. They provide superior visual capability over unaided night vision, but any reduction in goggle performance can have a serious effect on flight safety and operational effectiveness. This study shows that the use of the ANV 20/20 focusing aid provides an effective method for aircrew to obtain a better visual capability than is currently obtained by focusing on distant features of the landscape or distant lights. Visual acuities using the current and proposed focusing methods were compared in 50 aircrew. The visual acuity showed an average improvement of 18% with the proposed method compared with the current method. This was found to be statistically significant (p < 0.01). Using the current method of focusing there was a significant (p < 0.01) difference in the visual acuity achieved between the right and left tubes/eyes. Using the ANV 20/20 there was no difference between tubes/eyes. ANV 20/20 was found to improve visual acuity when using NVG as well as enabling the user to achieve equal visual acuities with both eyes.