refractiveerror-200625072525.pptx. .

Refractive error

1. Refractive Error Refractive error means that the shape of your eye does not bend light correctly, resulting in a blurred image. The main types of refractive errors are myopia (nearsightedness), hyperopia (farsightedness), presbyopia (loss of near vision with age), and astigmatism.

2. Refraction Means Refraction is the bending of light as it passes through one object to another. Vision occurs when light rays are bent (refracted) as they pass through the cornea and the lens. The light is then focused on the retina. The retina converts the light-rays into messages that are sent through the optic nerve to the brain. The brain interprets these messages into the images we see.

3. Signs and Symptoms Blurred vision Double vision Haziness (uncleared) Glare or halos around bright lights Squinting Headaches Eye strain

4. Risk factor / Etiology Genetics Marfan syndrome X-linked disorders Environmental Re a d i ng ha s also b e en found to be a pr e dictor of myopia in children. Socioeconomic status and higher levels of education ha v e also been r e p o rted to be a ri s k fact o r for myopia.

5. T ypes

6. Myopia (nearsightedness) It is a condition where objects up close appear clearly, while objects far away appear blurry. For treatment use concave lens

7. Hyperopia (farsightedness) People with hyperopia can usually see distant objects well, but have trouble focusing on nearby objects. For treatment use convex lens

8. Astigm a tism It is a condition in which the eye does not focus light evenly onto the retina, the light-sensitive tissue at the back of the eye. This can cause images to appear blurry and stretched out. Cylindrical error occurs when the incoming light rays are unable to reach a common focus within the eye. Astigmatism distorts or blurs vision for both near and far objects.

9. Presbyopia It is an age-related condition in which the ability to focus up close becomes more difficult. As the eye ages, the lens can no longer change shape enough to allow the eye to focus close objects clearly. When the flexibility of the lens declines, typically due to age. The individual would experience difficulty in near vision, often relieved by reading glasses, bifocal, or progressive lenses

10. Diagnostic Evaluation Dilating Eye Drops

11. Retinoscopy A hand held instrument called a retinoscope projects a beam of light into the eye. When the light is moved vertically and horizontally across the eye, the examiner observes the movement of the reflected light from the back of the eye.

12. This reflection is called red reflex. The examiner then introduces lenses in front of the eye and as the power of the lenses changes, there is a corresponding change in the direction and pattern of the reflection. The examiner keeps changing the lenses until reaching a lens power that indicates the refractive error of the patient.

13. Manag e ment R e fractive erro r s can be co r re c ted with eyegla s ses, contact lenses, or surgery Eyegl a ss e s are t h e simplest and safest way t o cor r e c t refractive errors.

14. In many cases, contact lenses provide clearer vision, a wider field of vision, and greater comfort. They are a safe and effective option if fitted and used properly. It is very important to wash your hands and clean your lenses as instructed in order to reduce the risk of infection. Contact Lens

15. Refractive Surgery