ASTIGMATISM

By Jim VanZile

Normal Vision

When a person first sees something light is reflected off the object into the eye through the pupil and cornea. The light is transformed into an image on the retina. Visual receptors called rods and cones use chemicals called visual pigments change the image in to electrical signals. These electrical signals pass through the optic nerve into the brain and the image is completed (Goldstein, 2014). Recognizing something that has been seen before can involve the Gesalt Principle. The Gesalt Principle includes two factors, sensations and perception (Goldstein, 2014). Goldstein explains that sensation is the stimulation process while perception is recognizing what is being seen through past experiences.

Symptoms of Astigmatism

  • Headaches
  • Eye Strain
  • Squinting
  • Distorted or blurred vision at all distances
  • Difficulty driving at night


Provided by the National Eye Institute

Understanding Astigmatism

Astigmatism is described as a condition when light does not focus into the retina correctly causing vision to blur (National Eye Institute, 2015). The National Eye Institute explains that a normal cornea of an eye is round like a basketball. When a the eye is misshaped and the form resembles a football astigmatism will occur.

Treating Astigmatism

Treating astigmatism can be done in various ways. Suggested methods include; glasses, rigid contact lenses, or laser in situ keratomileusis (LASIK) surgery (Ghoreishi, Beni, & Beni, 2014). It is suggested that the each specific patient be evaluated to determine what procedure is best suited for them.

References

Ghoreishi, M., Beni, A. N., & Beni, Z. N. (2014). Visual outcomes of topography-guided excimer laser surgery for treatment of patients with irregular astigmatism. Lasers in Medical Science, 29(1), 105-111. http://dx.doi.org/http://dx.doi.org/10.1007/s10103-013-1282-9


Goldstein, E. B. (2014). Sensation and perception (9th ed.). Belmont, CA: Wadsworth.


National Eye Institute. (2015). Astigmatism. Retrieved from https://nei.nih.gov/healthyeyes/astigmatism