Yeva Vision
The content of the prescription
3 cups
Flour
Right eye
Far vision
1½ cups
Butter
Left eye
[OG or OS]
Value of astigmatism
Orientation of astigmatism
Visual acuity
20/20 in feet or 6/6 in meters
Addition for near vision
HPS
The number indicated in the column <<SPH>> indicates the value of your ametropia.
When preceded by the sign << - >> represents the degree of myopia.
When preceded by the sign << + >> represents the degree of hyperopia.
CYL
The number entered in the <<CYL>> column expresses the importance of astigmatism.
AXIS
The value indicated in the column <<AXE>> corresponds to the orientation of the power of astigmatism.
PRISM / BASE
Sometimes there may be a number in the <<PRISME>> column followed by information in the <<BASE>> column indicating how the prism should be positioned.
ADD
On the prescription for people over 40, there is usually a number, preceded by the sign << + >> , on the line <<ADD>> . It is the additional power necessary for the presbyopic eye to have a comfortable near vision.
Visual acuity
A / V
Expressed in fractional form;
The numerator = distance at which the test is done.
The denominator = distance at which an average eye should be able to read the test.