CONVERT A REFRACTION

FROM SPHERE-CYLINDRICAL, TWO CYLINDER AND VECTOR FORMAT TO --->

PURPOSE

Given a refraction found in usual clinical notation, and therefore the Sphere (ESF) and the Cylinder (CIL) in Dioptras and the Axis (EJE) in Degrees, it is converted to other formats.

Spherical Equivalent

EE = ESF + CIL / 2

Cylinder Transposition

ESFT = ESF + (CIL)

CILT = - (CIL)

AXIS = 90 + AXIS

Two-Cylinder Notation

CIL1 = ESF

AXIS1 = 90 + AXIS

CIL2 = (sign of CIL1) (ESF + CIL)

AXIS2 = 90 + AXIS1

Vector Notation

Refractive defect represented by a vector located in a three-dimensional euclidean space. The vertex of the vector is indicated by 3 coordinates obtained using the following formulas:

M = Spherical equivalent (AXIS Z)

M = ESF + CIL / 2

J0 = Power of a Jackson cross cylinder whose axis is oriented at 0-90 (X AXIS)

J0 = - (CIL / 2) X Cosine (2 X AXIS)

J45 = Power of a Jackson cross cylinder whose axis is oriented 45-135 (Y AXIS)

J45 = - (CIL / 2) X Sinus (2 X AXIS)

Furthermore, with these data we can calculate the length of this refractive vector, an indicator of the average refractive defect (analogous to EE) and used in the Raash formula to calculate the Theoretical Visual Acuity.

To perform the calculation the cylinder must be at + (median less flat).

METHOD

Enter the refraction and press the execute button.

BIBLIOGRAPH

1.Optica for the surgeon facorefractivo, SEO, Ramn Ruiz Mesa, 2015, pg 50-52.

2. Statistical analysis of refractive data, Revista Cubana de Oftalmologa, Waldemar Baldaqun, Suzel Lapido Polanco, Vol 27 N 2