1. Module 3: Topics 1-3 Vision and Driving
Visual Fields
Line of Sight/Path of Travel
Locating Vehicle Blind Zones

2. Visual Fields

3. THE FOCAL VISION AREA
Located at the center of the central vision area, the fovea is a small part of the retina and is responsible for our highest visual acuity
3-5 degrees of useful information

4. THE CENTRAL VISION AREA
Central Vision Area (Inner Fringe)
An area 35 to 38 degrees around foveal vision used for:
Referencing Vehicle Position to the Roadway
Viewing the path of travel

5. THE PERIPHERAL VISION 180-190 degrees of useful information
Used to see
Objects to the side
Motion/Movement Changes to the side
Color Changes to the side

6. PERIPHERAL VISION AND THE DRIVING TASK
Drivers use peripheral vision to:
See color and object movement
See signal changes, road signs, warning lights on the dashboard
Monitor traffic
Stay within the lane

7. Area a Driver Can See While Looking Straight Ahead
FIELD OF VISION
Area a Driver Can See While Looking Straight Ahead
Viewing Path of Travel
Central Vision
Focus Vision
Targeting
(Reading Signs)
Peripheral Vision
Motion & Color Changes
90 percent of driving decisions are based on information gathered with the eyes.

8. VISIBILITY
Ability to see the roadway and be seen by other drivers and pedestrians

9. EFFECTIVE USE OF VISUAL FIELDS
The Three Visual Fields
Focal Vision
Visual Lead, Targeting, Signs, Signals
Central Vision
Referencing, Path of Travel
Peripheral Vision
Motion and Color Changes

10. DEPTH PERCEPTION
Need both eyes to judge the distance between two objects
Depth perception allows you to:
judge gaps in traffic when turning, merging, or passing
judge distance when approaching a vehicle or obstruction

11. POOR DEPTH PERCEPTION Stop too far from the stop line or intersection
Stop too close to vehicles ahead
Move into gaps that are too small
Look for gaps that are larger than needed to perform a maneuver
Follow other vehicles at unsafe following distance
Hit parked cars when parking
Have “close calls” when entering traffic, passing, etc.

12. HEADLIGHTS
Drive with your low-beam headlights on during daylight hours.
During the daylight a vehicle without headlights is visible from about a half mile away.
With headlights on, the same vehicle is visible from nearly a mile away.
Virginia Law requires low beam headlights to be on whenever your windshield wipes are on.
Dim headlights within 500 feet of an approaching vehicle
Dim headlights within 200 feet travelling behind another vehicle.

13. VISUAL SKILLS VOCAB
Focal Vision: used to read or identify distinct objects.
Central vision: fringe area around the focal vision. It is used to judge depth and position.
Peripheral vision: outer vision fields. Motion changes are often detected in the peripheral vision area
Target: a fixed object that appears at the end of your path of travel.
Path of Travel: where the driver directs and intends for the vehicle to travel.
Vehicle operating space: the area around the vehicle which is not visible to the driver.

14. GOOD VISUAL HABITS
Recognizing a dangerous driving situation in advance allows time to plan evasive maneuvers.
Drivers with poor visual habits:
• Do not prepare for stops or turns far enough in advance.
• Do not notice traffic tie-ups in advance.
• Become trapped behind large trucks, or slow-moving vehicles.
• Are often surprised.
• Are unaware of vehicles about to pass.
• Are unaware of their own speed.
• Drive with turn signals flashing although they do not intend to turn.
• Drive with mirrors that are dirty or out of adjustment.
• Drive with fogged, dirty or partially blocked windows.
• Become distracted easily.
• Do not respond to changes in the traffic environment.

15. VISION IS AFFECTED BY Speed Fatigue Drugs Smoke Poor weather Age
Darkness
Glare
Inattention
Smoke
Age
Dirty Windshield
Poor Windshield Wipers
Poor night vision
Night Blindness

16. Central vision decreases and blurs Peripheral vision decreases
AS SPEED INCREASES
Central vision decreases and blurs
Peripheral vision decreases
Changes in steering exaggerate vehicle movement
Vision Field Narrows

17. WHAT COULD YOU DO TO MANAGE VISIBILITY IN THIS CAR?

18. THE CENTRAL VISION AT NIGHT
The human eyes field of vision is much smaller without the help of natural light
Depth perception, visual acuity, and color recognition are all compromised at night
Minimize glare by looking at the bottom right of the road to avoid approaching headlights
Keep it dark in the car
Slow down to give yourself longer to react

19. NIGHT TIME PERIPHERAL VISION
Is reduced dramatically due to lack of light to retina and glare
While Focal and Central Vision are also reduced, they become more critical for searching for problems

20. DRIVING AT DUSK
Be especially alert at dusk. The sky still may be bright, but objects on the road can merge with shadows and fade into the darkness.
Bad weather
If the weather becomes too bad, pull off the road to a rest area or parking lot and wait for conditions to improve.

21. VISIBILITY Advance preparations:
Clear and clean inside / outside of windows
All lights are working
Defroster, wipers and washer are working
Adjust mirrors and seat
Keep sunglasses handy
Remove obstructions in car: packages, things hanging from mirrors
Turn on headlights….Day or night
Driving with low beams
Signal intentions well in advance
Avoid driving in another’s blind spot
Always wear glasses / contacts if needed
Shield from glare with sunglasses

22. LINE OF SIGHT (LOS) RESTRICTIONS
Vision is blocked, speed and position adjustments may be needed until LOS is restored