What is amblyopia, and how is it treated? Refractive amblyopia is the most common type of lazy eye. It occurs most commonly when a child is born with a high refractive error (blurriness requiring a glasses prescription to correct) in one eye.
So what is refractive amblyopia? Because one eye has good vision and the other does not, the vision of the child does not develop normally. This often results in the suppression of the foveal (central) part of the weak eye.
Because the vision of one of the eyes is not well developed, the brain does not develop proper binocular vision. It never learns to use both eyes together, which means that the person never develops depth perception (3d vision using both eyes).
To a person suffering from a binocular vision disorder like refractive amblyopia it may not seem as though their vision is impaired while driving. The vision in their good eye is often perfectly fine, and it is true that a person with a lazy eye can be perfectly fine driving.
But, there are several visual deficits that can have an effect on the driver without good 3D vision.
It is common for the vision on the side of the weak eye to still be present, but not as useful as the peripheral vision in the stronger eye.
The brain has to spend mental energy to try to combine the information coming from the strong and weak eyes. The eyes may not align properly while tracking movements objects, making it take a longer time and be more taxing to drive than for someone without vision impairment.
One of the purposes of depth perception is to quickly allow you to identify dangerous, moving things. A situation where this often comes up is when making a left turn (in the US) onto a busy road without a traffic signal. Oncoming cars can be close to dead on, so the only information present to the stereo blind person is the slowly increasing size of the oncoming car.
Let's cover a couple of frequently asked questions.