REFRACTIVE ERROR BY DNYANESHWAR BHAGWAN POTFODE

1. Refractive error
DNYANESHWAR B. POTFODE
OPHTHALMIC OFFICER

2. Vision testing
• Normal distance vision is recorded from 6
meter with snellen chart.
• Well illuminated light
• Chart should be parallel to patient.
• Vision less than 6/6 that patient has refractive
error.

3. Snellen chart

4. Emmetropia
• When parallel rays of light
coming from infinity and focus on
the retina when accommodation
at rest is called as emmetropia.
Normal eye means emmetropia.

5. Emmetropia – Normal eye

6. Normal parameter
• Normal curvature of cornea
• Normal axial length of eyeball

7. Ametropia
• Refractive error also called as Ametropia.
• Myopia
• Hypermetropia
• Astigmatisma
• Presbyopia

8. Myopia
• When parallel rays of light
coming from infinity and focus
infront of the retina when
accommodation at rest is called
as myopia.

9. Myopia

10. Etiology

12. Treatment
• Myopia is corrected by concave
lens
• Spectacle
• Contact lens
• Surgery

13. Hypermetropia
• When parallel rays of light
coming from infinity and focus
behind the retina when
accommodation at rest is called
as hypermetropia.

14. Hypermetropia

15. Etiology

16. Treatment
• Hypermetropia is corrected by
convex lens.
• Spectacle
• Contact lens
• Surgery

17. Astigmatism
• When parallel rays of light coming from
infinity and focus in line not in single point
when accommodation at rest is called as
astigmatism.

18. Etiology
• Irregularity of corneal curvature
• Irregularity of lens curvature
• Irregular cataract development
• Trauma to cornea

19. Type of astigmatism
• Simple astigmatism
• Compound astigmatism
• Mix astigmatism

20. Simple astigmatism
• One rays focus on the retina and other either
infront and behind retina.

21. Compound astigmatism
• Both rays either infront of retina or behind
retina.

22. Mix astigmatism
• One rays infront of retina and other behind
the retina.

23. Treatment
• Astigmatism is corrected by cylindrical lens.
• Spectacle
• Contact lens
• Surgical

24. Presbyopic
• Decrease lens accomodation with age is called
presbyopia.
• Its start with age of 40 years.
• It corrected with convex lens

26. complication
• Uncorrected refractive error cause
• 1) Amblyopia
• 2) Squint
• 3) Diplopia