California Driver Handbook - Driver Readiness
You need good vision to drive safely (see the Vision section ). If you cannot see clearly, you cannot judge distances or spot trouble, and you will not be able to make the best judgments. You also need to see peripherally or “out of the corner of your eye” to spot vehicles coming up beside you while your eyes are on the road ahead. Have your eyes checked annually or biennially.
The sound of horns, a siren, or screeching tires can warn you of danger. Sometimes you can hear a vehicle but cannot see it, especially if it is in your blind spots.
Even people with good hearing cannot hear well if there is too much noise. It is against the law to wear a headset or earplugs in both ears while driving.
Hearing problems can come on so slowly that you do not notice them. Have your hearing checked periodically. Drivers who are deaf or hard of hearing can adjust their driver safety habits by relying more on their sense of sight to compensate for the loss of hearing.
Fatigued or Drowsy Driving
Fatigue or drowsiness can affect your vision and increase reaction time to hazards. Avoid driving if you are fatigued or drowsy.
The following will not prevent drowsy driving:
- Rolling down the window. Drinking/eating caffeine or sugar.
- Turning on or turning up the radio.
- Turning on the air conditioning.
The following will prevent drowsy driving:
- Getting enough sleep before driving, and not driving until rested.
- Driving with a passenger, and switching drivers when you start to feel drowsy.
- Taking regular rest stops even if you are not tired.
- Calling a ride service or friend to take you to your destination.
Remember that all medications, prescription or over-the-counter, are potentially dangerous and can impair your driving. Over-the-counter medicines that you take for colds and allergies can make you drowsy and affect your driving ability. If you must take medication before driving, find out the effects of the medication from your physician or pharmacist. It is your responsibility to know the effects of the medications you take.
Before you decide to drive, do not:
- Mix medications, unless directed by your physician.
- Take medications prescribed for someone else.
- Mix alcohol with your medications (prescribed or over-the-counter).
Health and Emotions
Emotions can affect the way you drive. Do not let your emotions interfere with safe driving. Use your good judgment, common sense, and courtesy when you drive. Follow the recommended safe driving rules.
Discuss health concerns, such as poor vision, heart problems, diabetes, or epilepsy with your physician and follow their advice. Notify DMV if you have a condition that might affect your ability to drive safely.
Conditions Physicians Must Report
Physicians and surgeons are required to report patients at least 14 years old and older who are diagnosed as having lapses of consciousness, Alzheimer’s disease, or related disorders (California Health & Safety Code [CHSC] §103900).
Although not required by law, your physician may report to DMV any other medical condition that they believe may affect your ability to drive safely.