Kowa AP-7000 User Manual
35
3
Calculating near correction value from distant correction value
This function should be used to calculate a near correction value by inputting a distant correction value in “ 2
” above when a lens is used.
If the date of birth is entered, [Distant >> near] is active.
When you press [Distant >> near], the calculated near correction value is input.
A near correction value is calculated from a distant correction value in the following method.
When you press [Distant >> near], the calculated near correction value is input.
A near correction value is calculated from a distant correction value in the following method.
No need to correct the distorted vision when the Cyl value is 0.25D or less.
Sphere equivalent value is used for distorted vision when Cyl is 1.25D or less.
(Spherical equivalent value) = (Spherical diopter power) + (Cylindrical diopter power) / 2
(Spherical equivalent value) = (Spherical diopter power) + (Cylindrical diopter power) / 2
The spherical diopter power is calculated based on the table shown below.
Near spherical diopter power calculation table
Distance
Age
More than
＋
1
0
– 0.50
– 1.00
– 1.50
– 2.00
– 2.50
– 3.00
Less than
– 3.00
Less than
30
Distance
＊
＊
＊
＊
＊
＊
＊
Distance
＋
3.25
30 to 39
Distance
＋
1.00
＋
1.00
＋
0.50
＊
＊
＊
＊
＊
Distance
＋
3.25
40 to 44
Distance
＋
1.50
＋
1.50
＋
1.00
＋
0.50
＊
＊
＊
＊
Distance
＋
3.25
45 to 49
Distance
＋
2.00
＋
2.00
＋
1.50
＋
1.00
＋
0.50
＊
＊
＊
Distance
＋
3.25
50 to 54
Distance
＋
2.50
＋
2.50
＋
2.00
＋
1.50
＋
1.00
＋
0.50
＊
＊
Distance
＋
3.25
55 to 59
Distance
＋
3.00
＋
3.00
＋
2.50
＋
2.00
＋
1.50
＋
1.00
＋
0.50
＊
Distance
＋
3.25
More than
60
Distance
＋
3.25
＋
3.25
＋
2.75
＋
2.25
＋
1.75
＋
1.25
＋
0.75
＊
Distance
＋
3.25
*: No lens required.
[Example of calculation]
[Example of calculation]
1. 48-years-old Distance (S: +2.00, C: +2.00, A: 120°)
Spherical: +4.00D
Distorted vision: +2.00D, Adjust Axis to 120° of the lens holder.
2. 60-years-old Distance (S: +1.50, C: +1.00, A: 70°)
Spherical: +5.25D (Spherical equivalent value: +2.00D, Addition power by age: +3.25D)
3. 32-years-old Distance (S: –3.00, C: +0.25, A: 40°)
No correction required
4. 18-years-old Distance (S: –4.00)
Spherical: –0.75D
5. 65-years-old Emmetropic (S: +0.00)
Spherical: +3.25D
6. 40-years-old Distance (S: –1.00)
Spherical: +0.50D