Runway and Terrain Slopes Illusion...................17-10 Featureless Terrain Illusion ................................17-10 Water Refraction.................................................17-10 Haze ....................................................................17-10 Fog ......................................................................17-10 Ground Lighting Illusions...................................17-10 How To Prevent Landing Errors Due to Optical Illusions .....................................................17-10 Motion Sickness .....................................................17-12 Carbon Monoxide (CO) Poisoning ........................17-12 Stress ......................................................................17-12 Fatigue ....................................................................17-13 Exposure to Chemicals...........................................17-13 Hydraulic Fluid...................................................17-13 Engine Oil...........................................................17-14 Fuel .....................................................................17-14 Dehydration and Heatstroke...................................17-14 Alcohol ...................................................................17-15 Drugs ......................................................................17-16 Altitude-Induced Decompression Sickness (DCS).. 17-18 DCS After Scuba Diving ....................................17-18 Vision in Flight ..........................................................17-19 Vision Types ..........................................................17-20 Photopic Vision ..................................................17-20 Mesopic Vision...................................................17-21 Scotopic Vision...................................................17-21 Central Blind Spot ..................................................17-21 Empty-Field Myopia ..............................................17-22 Night Vision ...........................................................17-22 Night Blind Spot .................................................17-22 Dark Adaptation..................................................17-23 Scanning Techniques .........................................17-23 Night Vision Protection ......................................17-23 Self-Imposed Stress ...........................................17-25 Distance Estimation and Depth Perception .......17-25 Binocular Cues....................................................17-26 Night Vision Illusions ............................................17-26 Autokinesis .........................................................17-26 False Horizon......................................................17-26 Reversible Perspective Illusion...........................17-26 Size-Distance Illusion.........................................17-27 Fascination (Fixation).........................................17-27 Flicker Vertigo....................................................17-27 Night Landing Illusions..........................................17-27 Enhanced Night Vision Systems ............................17-27 Synthetic Vision System.....................................17-28 Enhanced Flight Vision System..........................17-28 Chapter Summary ......................................................17-29 Appendix A Performance Data for Cessna Model 172R and Challenger 605.............................................A-1 Appendix B Acronyms, Abbreviations, and NOTAM  Contractions .......................................................B-1 Appendix C Airport Signs and Markings...............................C-1 Glossary ..............................................................G-1 Index ......................................................................I-1 xvi 