Refractive errors.

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Presentation transcript:

Refractive errors

Refractive surfaces of the eye Cornea : main Lens : accommodation

emmetropia With accommodation completely relaxed parallel rays will come to point focus on the retina

Myopia With accommodation completely relaxed parallel rays will come to point focus in front of the retina Axial Refractive Concave spherical

Hypermetropia With accommodation completely relaxed parallel rays will come to point focus behind of the retina Axial Refractive Convex spherical

Astigmatism Parallel rays dose not come to point focus Line focus Cylindrical error

presbyopia Loss of accommodation Difficulty in near vision Bifocal or multifocal lenses

Refractive surgery Incisional Photorefracrtive corneal surgery ICL Clear lens extraction

Thank you

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