In order to see clearly, light rays from an object must focus onto the inner back layer of the eye. If light rays are not focused on the retina, a refractive error is present.

The eye works like a camera. There is an opening in the front (the pupil), a focusing lens inside (crystalline lens) and a light-sensing portion at the back (the retina). Refractive errors occur when light rays from an object aren’t focused onto the retina.


Myopic (near-sighted) patients have blurry distance vision which can cause issues seeing the chalkboard, watching TV, playing sports as well other tasks that require good distant vision. The person can usually see well for reading and other near tasks (computers, playing games, etc.).


It is normal for hyperopia (far-sighted) to present early in life, but treatment may not be needed because the focusing muscles inside the eye help hyperopic patients to focus. If someone has a higher hyperopic prescription, the focusing muscles may not be able to keep the vision clear. When this occurs, patients can experience crossing of the eyes, blurred vision or discomfort may develop.


Astigmatism is caused by a curvature in the surface of the eye. Patients with astigmatism have eyes that are more like a football instead of a spherical object (i.e. soccer ball). Patients with significant astigmatism may notice blurred and/or distorted images.


If someone has a different prescription in each eye they are considered ansimetropic. This can cause a child to be at a higher risk for developing amblyopia if the vision isn’t balanced with glasses. In some cases patients may even need treatment with patching and/or drops.

Children’s Eye Care provides this information for general educational purposes only. It should not be construed as personal medical advice. Information published on this website is not intended to replace, supplant, or augment a consultation with an eye care professional. Children’s Eye Care disclaims any and all liability for injury or other damages that could result from use of the information obtained from this site.