Amblyopia, also referred to as lazy eye, is defined as decreased central vision in one or both eyes which is not correctable with prescription lenses. Amblyopia is the result of a non-disease process or abnormality that interferes with the normal development of the eyes and visual system.

Development of the visual system begins at birth with normal use of the eyes. Good vision is encouraged to improve as the infant properly utilizes their eyes. The eyes and vision evolve as the child ages, and continue to change through the first decade of life. Any interference with this process can negatively impact potential visual ability.

Amblyopia is caused by several abnormalities. In the case of strabismus, or misalignment of the eyes, the eyes do not work together and one or both eyes may turn in, out, up, or down. Amblyopia may also be caused by vision problems like nearsightedness, farsightedness, and astigmatism. In cases where there is a large degree of difference in visual acuity between the eyes, both eyes may not have equal focusing ability. Therefore, the 'weaker' eye may not develop normally, and the child may favor the stronger eye. Rarely, certain types of cataracts or opacities may cause amblyopia.

In each of the previous causes, the brain receives a good, sharp image from one eye, and a blurry or fuzzy image from the other eye. The brain cannot combine the images, and eventually ignores the eye with the poor image. If left uncorrected, this weaker, or lazy eye, will develop amblyopia.

Unless an eye turn is visible, amblyopia often has no symptoms and may go unnoticed by even the most perceptive parents. In the majority of cases, amblyopia must be detected by checking vision and the visual system. In very young children and infants, vision may be estimated by how well they follow a small object with one eye covered. A normal eye will look directly at the object while an amblyopic eye may look to the side.

Once amblyopia has been diagnosed, treatment may consist of a combination of the following:

  • Patching of the good eye
  • Eye drops to blur the good eye
  • Prescription lenses
  • Prism
  • Vision therapy