visual acuity
- 1. VISUAL ACUITY AND ITS TESTING
- 2. ? Visual acuity ¡ö Visual acuity is the measure of spatial resolution Of the eye or,in other words an estimation of its ability to discriminate between two separate points.
- 3. Principle ¡ö The two distinct points is only be recognized as separate When they subtend an angle of 1minute of arc At nodal point of the eye
- 9. Why needed ¡ö To test visual function ¡ö Refractive status of the eye ¡ö Criteria for ¡ö Person fitness to drive ¡ö Elligiblity for entrance in profession
- 20. MEASUREMENT OF VISUAL ACUITY IN INFANTS.
- 21. OKN (optokinetic Nystagmus test ) ¡ö Commonly used test on neonates ¡ö Test object moves in one direction. ¡ö Based on observation of perpendicular eye Movement ¡ö In this test nystagmus is elicted By passing A succession of black n white stripes of okn drum
- 25. Visual evoke response (VER)
- 26. Teller chart
- 27. ASSESMENT OFVISUAL ACUITY OF 1TO 3 YEARS
- 29. Worth ivory Ball test
- 30. Marble game test ¡ö Place marble in the hole of the box ¡ö Intended to monocular visual function ¡ö Vision is notef as usefull or less usefull
- 31. ASSESEMENT OFVISUAL ACUITY IN PRESCHOOL CHILDREN(3-5YRS)
- 32. Landolt c chart
- 33. Broken wheel test ¡ö Cards are presented With picture of cars, very familiar to the child ¡ö Two cards are held before the child,he simply has to recognize which one is broken. ¡ö It consist of 8 pairs of test cards and a sample pair of card
- 35. Allen card
- 36. ASSEMENT OFVISUAL ACUITY ABOVE 5YEARS
- 37. Key points
- 38. Snellen visual acuity chart
- 39. Continue..
- 40. Continue..
- 41. Disadvantages of snellen chart
- 42. Logmar chart ¡ö It is logarithm of minimum angle of resolution. ¡ö It consist og 5 letters in each line ¡ö Based of minimum angle of resolution ¡ö Have regular progression in the size and spacing Of letter from one line to next
- 43. Continue ¡ö Each letter has score value of 0.02 log units ¡ö Since there are 5 letters Per line The total score For a line On the Logmar chart represents a change of 0.1 log units . ¡ö LogmarVA =0.1 +value Of best line read ¨C 0.02 ¡Á(number of optotypes read)
- 46. Jaeger chart