Diplopia or Double Vision:
Diplopia or Double Vision is a visual impairment consisting in perceiving two images of the same object. It can be horizontal, vertical or diagonal, depending on the place where the dual images appear (beside, below, above or diagonally with regard to the object).
There are also different types of strabismus that can cause double vision: Oculomotor nerve palsy; Strabismus that appears after eye surgery; Orbital trauma; Thyroid disorders; Some forms of child strabismus that last into adulthood; Strabismus of the myopic patient; Neurological diseases (such as myasthenia gravis); Sensory strabismus (occurs when one of the two eyes has very low vision).
Sometimes, diplopia only affects one of the two eyes (monocular) and does not disappear when covering it. This kind of double vision is usually associated with other diseases that affect eye structures, which prevent eyes from fusing images, hence resulting in double vision.
Adult strabismus can arise as a result of childhood strabismus or be secondary to different diseases and processes. Depending on its many different causes, there are four main groups of strabismus, each one of which must be treated specifically:
Paralytic: The muscles responsible of moving and focusing the eye are much weaker, generally due to ischemias, tumours or neurological pathologies.
Restrictive: this is due to a mechanical problem arising from prior eye surgeries and orbital fractures or trauma, as well as secondary to thyroid diseases or high myopia.
Essential: this often comes from childhood, although it might be just the opposite and be a result of ageing due to laxity of the tissues involved in eye movements.
Sensorial: associated to bad eyesight, as it arises when one of the two eyes cannot see or has very limited vision.
To assess the degree of ocular deviation and the type of strabismus in order to ascertain subsequent treatment, a complete ophthalmological examination is performed that may sometimes require specific tests to assess the disease.
Strabismus Surgery in Adults:
Strabismus surgery in adults is the treatment to correct this eyesight problem that consists of the loss of parallelism between both eyes insofar as they are not properly aligned and each one points in a different direction.