This is known as Esotropia.
Esotropia is sometimes referred to- incorrectly- as lazy eye.
In one study, over 50% of patients had strabismus,
The primary sign of Esotropia, obviously, is crossing of the eyes.
needs to be treated early in life to prevent amblyopia.
Acquired(or secondary) Esotropia, which develops later in life, can occur
for a variety of reasons:.
(Lazy eye in fact refers to amblyopia,
which can be a consequence of childhood Esotropia.).
Congenital Esotropia(also known as infantile Esotropia)
is usually detected during the first six months of life.
The appearance of crossed eyes in an infant is not always a sign of Esotropia;
The opposite of Esotropia is exotropia,
which is characterized by eyes that point outward, toward the ears.
It is the most common form of Esotropia in children,
and it is caused by uncorrected farsightedness(also known as hyperopia).
This type of squint can run in families,
although many children with congenital Esotropia have no other family members affected.
Movement of the eye outwards confirms that there is an Esotropia(ie the eye was turned inwards initially)
and vice versa for exotropia.
Commonly referred to as crossed eyes, Esotropia is a common type of strabismus in which one
or both eyes turn inward toward the nose.
Mechanical Esotropia may be seen in children with Duane syndrome,
an eye muscle disorder that can prevent outward movement of the eye(toward the ear).
Exotropia(also known as wall-eye or divergent strabismus)
differs from its opposite form, Esotropia(eye turns in toward nose), in that
exotropic eyes point outward or away from the nose.
Approximately 30% of patients with strabismus have a relative who is or was affected,
and most families are concordant for the type of strabismus(e.g., Esotropia or exotropia).
Infants and children with suspected Esotropia are typically evaluated by a pediatric ophthalmologist or optometrist,
who will review the child's medical and family histories and then perform an examination to determine the child's visual acuity.
There are other classifications which combine these elements with whether the problem is on near or distant gaze, whether there is accommodative ability or not and whether the problem changes over time(eg,
exotropia becoming an Esotropia).
A constant Esotropia is present all the time, whereas intermittent Esotropia may become apparent only when
looking at close objects or only when looking at distant objects, or if the affected person is tired or sick.
Sensory Esotropia: A person with this condition suffers from reduced
visual acuity in one eye, which hinders or disrupts the process of fusion in normal binocular vision(binocular vision is the coordination of both eyes so that the separate and slightly dissimilar images seen by each eye are appreciated as a single image).