Astigmatism is a vision problem that occurs when light entering the eye is unable to be brought to a single, clear focus, resulting in blurred vision.

Astigmatism is often caused by the cornea, or front surface of the eye, having an irregular rather than a round curvature. It may occur with nearsightedness (myopia) or farsightedness (hyperopia) and can be corrected with glasses or contact lenses.

Hyperopia is the inability to see close objects easily and clearly. Usually, a farsighted person can see objects in the distance with clarity.

Children and young adults with moderate amounts of farsightedness may exert greater effort when focusing to keep close objects in focus . Over time, this added effort may result in the development of a number of vision problems including: eye strain, periodic blurred vision, headaches after close work, and feelings of fatigue.

For some children (even those who see 20/20 vision), anti-stress reading glasses can help relieve vision problems by reducing the focusing effort.

Myopia, or nearsightedness, is the inability to see objects at a distance clearly. Myopia usually develops in childhood and may progress into the early adult years. Risk factors for the development of myopia include a family history of nearsightedness, visual stress from close work, or using a computer.

Recommendations to help slow progression include increasing time spent outdoors, limiting near-vision tasks, and in some cases specialty contact lenses.

The ability to focus the eyes to see clearly up close, to change focus from distance to near and back again, and to maintain clear focus for an extended period of time.

Poor eye focusing ability can cause headaches, words going in and out of focus when reading. It can also make it difficult to concentrate on near vision tasks (reading and writing) and copying from the board in school.

Amblyopia is reduced vision in one or both eyes, not fully correctable with eye glasses, as a result of the eye not receiving adequate use during early childhood. This most often it results from either misalignment of a child’s eyes or a decrease in image quality seen with one or both eyes due to a large uncorrected prescription.

When one eye is affected the brain may ignore, or suppress, the vision development in that eye. This causes the brain to develop deficient visual abilities which frequently impacts a child’s ability to learn and limits 3D vision (stereopsis).

The ability of both eyes to work together as a team. Good eye coordination, a skill that must be developed, keeps the eyes in alignment. Poor eye coordination comes from a lack of adequate vision development.

Binocular vision dysfunction can lead to difficulties with reading, headaches, double vision, and eye strain.

This is a commonly seen binocular vision problem where the two eyes don’t turn in correctly. When we read our eyes have to turn in and they have to point to the same place on the page.

If one eye doesn’t line up with the other it can cause problems with reading, such as loss of place, loss of concentration, reading slowly, eyestrain, headaches, blurry vision and double vision.

The ability to smoothly and accurately move the eyes along a line of print or follow a moving target with our eyes.

Poor eye tracking can result in losing one’s place when reading, skipping words and/or lines, having to re-read materials, and difficulty copying from a book or the board in the classroom.

An inability of the two eyes to aim at the same place at the same time. This can result in an eye turning in, out, up or down.

Strabismus may cause periods of double vision and/or suppression (brain ignores eye that is turned). If untreated this condition can lead to amblyopia (see above) and reduced 3D vision (stereopsis). These concerns can cause difficulties with reading academic work.

The ability to integrate visual information with gross and fine motor movements. Inadequate visual motor integration can result in clumsiness and difficulty with handwriting.

The process by which the brain interprets and understands the visual information received by the eyes. Aspects of visual perception include visual memory, size and form perception, directionality and color perception.

Poor visual information processing may contribute to letter reversals and cause difficulty with reading comprehension and spelling.