Determine Trial Lens
HFA3 Instructions for Use
2660021166131 Rev. A 2018-11
B-2
Note: If the patient is aphakic or needs a high refractive power such as +8.00 D, contact lenses may
provide the best visual field testing conditions.
Age
Distance R
x
–
0.50
Distance R
x
–1.00
Distance R
x
–1.50
Distance R
x
–2.00
Distance R
x
–2.50
Distance R
x
–3.00
Distance R
x
over –3.00
Under 30
No trial lens
needed
No trial lens
needed
No trial lens
needed
No trial lens
needed
No trial lens
needed
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
30–39
+0.50 D
No trial lens
needed
No trial lens
needed
No trial lens
needed
No trial lens
needed
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
40–44
+1.00 D
+0.50 D
No trial lens
needed
No trial lens
needed
No trial lens
needed
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
45–49
+1.50 D
+1.00 D
+0.50 D
No trial lens
needed
No trial lens
needed
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
50–54
+2.00 D
+1.50 D
+1.00 D
+0.50 D
No trial lens
needed
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
55–59
+2.50 D
+2.00 D
+1.50 D
+1.00 D
+0.50 D
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
60 & Over
+2.75 D
+2.25 D
+1.75 D
+1.25 D
+0.75 D
No trial lens
needed
(Dist. R
x
) + (+3.25 D) for trial lens
Table B-2 Spherical Trial Lens Correction for Central Visual Field Testing of Myopic Patients
