GMC 2003 Envoy XL Owner's Manual page 262

Since you can't see as well, you may need to slow
down and keep more space between you and
other vehicles.
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Slow down, especially on higher speed roads. Your
headlamps can light up only so much road ahead.
In remote areas, watch for animals,
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If you're tired, pull off the road in a safe place
No one can see as well at night as in the daytime.
But as we get older these differences increase.
A 50-year-old driver may require at least twice as much
light to see the same thing at night as a 20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the day in bright
sunshine you are wise to wear sunglasses. Your
eyes will have less trouble adjusting to night. But if
you're driving, don't wear sunglasses at night. They may
cut down on glare from headlamps, but they also
make a
lot
of things invisible.
and rest.
You can be temporarily blinded by approaching
headlamps. It can take a second or two, or even several
seconds, for your eyes to readjust to the dark. When
you are faced with severe glare (as from a driver
who doesn't lower the high beams, or a vehicle with
misaimed headlamps), slow down a little. Avoid starina
directly into the approaching headlamps.
Keep your windshield and all the glass on your vehicle
clean
-
inside and out. Glare at night is made much
worse by dirt on the glass. Even the inside of the glass
can build up a film caused by dust. Dirty glass makes
lights dazzle and flash more than clean glass would,
making the pupils of your eyes contract repeatedly.
Remember that your headlamps light up far less of a
roadway when you are in a turn or curve. Keep your eyes
moving; that way, it's easier to pick out dimly lighted
objects. Just as your headlamps should be checked
regularly for proper aim, so should your eyes be
examined regularly. Some drivers suffer from night
blindness
-
the inability to see in dim light
-
and
aren't even aware of it.
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