There are several categories of visual disability released by WHO. The impaired or low power vision is said to occur when the visual acuity is in range of 20/60 to 20/200 with corresponding visual field loss of greater than or equal to 20 degrees in the good eye with maximum correction. Loss of sight is said to occur if the visual acuity is less than 20/400 with corresponding visual field loss of greater than 10 degrees in the good eye with maximum correction. The visual acuity for upholding a driver’s license in the USA differ from state to state. Visual indications are the most important information for safe driving. It is reported that most of the road accidents in the US are associated with declining vision. Hence, the licensing authorities have introduced a least vision necessities for upholding driving rights. In case of blindness, the department of the motor vehicle will not provide driver’s license, if even not corrected by corrective lenses.
Can You Get a Driver’s License if You Are Legally Blind?
A Snellen’s chart is referred to an eye chart used to measure the clarity of visual sights. In the United States, clarity of vision is calculated by a method called Snellen visual acuity. If the person’s one eye is worse than 20/200, but another eye better than 20/200 with corrective lenses, then one is not considered as legally blind. Testing parameters commonly include uncorrected visual acuity in both eyes, best corrected visual acuity in both eyes, monocular and binocular visual fields.
The privileges for upholding driver’s license are similar in the USA and European Union’s countries. In the USA, most of the states require visual acuity of 20/40 with or without correction. It is measured in both eyes together and each eye separately. The minimum visual field requirement in most of the states must be in ranges from 110° to 140° horizontally. However, in some states, it doesn’t require as no diameter is specified for visual field requirements. To drive in the USA, the candidate has to clear the vision test, if unable to meet the specified standards, then the candidate must not drive within USA territory and cannot uphold driver’s license. Individuals who has visual acuity of 20/200 or even worse, upholding driver’s license is impossible in these cases.
In California, if the candidate fails to meet the required standard, a referral to an ophthalmologist for suggestion is required. He decides the ability of the candidate’s vision and prescribes eyeglasses. If the candidates clears the vision test, the driver’s license has to be renewed for every once in five years. If the candidate is 70 years old or more, visual examination is a must for renewal of license. If failed, candidate allowed for a supplementary driving test to determine their driving ability. In case, one has cleared the test, then the driver’s license can be renewed with certain limits added to the license. Limitations such as no driving on the freeway or night hours; sunrise to sunset driving only, prescription glasses, corrective contact lens, and special devices for vehicles.
In Iowa, driving is not acceptable for visual acuity less than 20/70. If visual acuity is < 20/50, but at least 20/70, then the driving speeds more than 35 mph is not allowed. In Massachusetts, mandatory testing of color vision is needed. The candidate must able to differentiate between green, amber, and red. If one is unable to differentiate between these colors then license is not given. In North Carolina and Texas, motor vehicle department will not provide driver’s license to individuals with a homonymous hemianopia i.e. loss of vision in the right or left halves of both eyes.
Ophthalmologist responsibility is to provide detailed information on candidate’s physical and mental states and ability to drive. In many cases, candidates are extracted for negotiating with doctors and come up with a driving plan. Medical doctor has the privileges to inform the State Department of motor vehicles with regard to the candidate’s medical condition pertaining to overall safety.
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