REFRACTION THEORY (STUDY EVERYDAY)

Question 1

Unaided visual acuity 6/12 (estimate)

Answer 1

1 diopter

Question 2

Unaided visual acuity 6/24-6/36 (estimate)

Answer 2

2 diopter

Question 3

Unaided visual acuity 6/60 (estimate)

Answer 3

3 diopter

Question 4

Fog eye

Answer 4

+2.0D lens

Question 5

which to neutralise first?

Answer 5

ALWAYS neutralise most positive (with light/fast against)

Question 6

refine sphere 0.25

Answer 6

less than 6/9

Question 7

refine sphere 0.5

Answer 7

6/9 - 6/18

Question 8

refine sphere 1.0

Answer 8

more than 6/18

Question 9

LogMar 0.0

Answer 9

6/6

Question 10

LogMar 0.1

Answer 10

6/7.5

Question 11

LogMar 0.2

Answer 11

6/9

Question 12

LogMar 0.3

Answer 12

6/12

Question 13

LogMar 0.4

Answer 13

6/15

Question 14

LogMar 0.5

Answer 14

6/19

Question 15

LogMar 0.6

Answer 15

6/24

Question 16

LogMar 0.7

Answer 16

6/30

Question 17

LogMar 0.8

Answer 17

6/38

Question 18

LogMar 0.9

Answer 18

6/48

Question 19

LogMar 1.0

Answer 19

6/60

Question 20

Refine sphere speech

Answer 20

Is that letter clearer with [place a +0.25 sphere in front of their eye] or without the lens
[remove the +0.25 sphere] or about the same?’

Question 21

Sphere logmar lenses (3)

Answer 21

Sphere 0.25 Logmar 0.0 , 0.1
Sphere 0.5 Logmar 0.2, 0.3 , 0.4
Sphere 1.0 Logmar 0.5 and above

Question 22

Cyl logmar (2) lenses

Answer 22

Jcc 0.25 logmar 0.0, 0.1, 0.2, 0.3
Jcc 0.5 logmar 0.4 and above

Question 23

Sphere 0.25 speech

Answer 23

‘Is that letter better, or just smaller and darker?’