Diplopia is the scientific name for a medical condition better known as double vision.
Although some cases of diplopia are not dangerous in any way, other times it can be extremely serious, and can seriously affect your long-term eyesight.
Most people take it for granted that they can focus their eyes every morning. Because of this, it can come as a real shock to wake up suddenly and realize that everything is coming through in double. For you to be able to see effectively with single vision, they’re re a lot of processes in the eyes that have to come together seamlessly.
The most important element in this orchestra of sight is the cornea. It's the clear film at the front of the eye that functions as a window to allow light to come through. It's almost wholly responsible for focusing all of the incoming light.
The lens of the eye is situated directly behind the pupil. It works with the residual light that comes through past the cornea. Light is not the only factor in how well the eye focuses.
The muscles of the eye, or extra ocular muscles as they're called, are responsible for rotating the eyes so that they unilaterally point towards the same point in space in front of the face.
The nerves take all of this information from the eye components and transmit it back to the brain, which processes the signals and turns it into what we know as eyesight.
In cases of diplopia, something is wrong with one or several of these individual components. Simply telling a doctor that you have double vision is not enough for him or her to make a diagnosis because technically diplopia is really a symptom, and not an illness.
And, depending on where the actual eyesight problem is occurring, this condition could indicate a much more serious problem that requires serious medical attention.
In less serious cases, the double vision is caused by a disruption in the cornea. The cornea is unable to filter the light coming in the proper way and so by the time the signal reaches the brain it's distorted from its true self. Sometimes this can happen because of an infection.
When it comes to the lenses, most people who have double vision actually have cataracts. This only happens though if the person has cataracts in both eyes.
If it's only in one eye, the other will still be able to correct for the problems seen by the affected eye. When there are cataracts in both eyes, they have trouble lining up, which results in double vision.
Double vision is something that you should always take seriously, even if it turns out to be a minor issue in the end.
As a general rule, a medical professional should check out any vision changes that happen either suddenly or over time.