Near point of convergence with RAF rule

Описание: Near point of convergence with RAF rule:
The near point of convergence is the point nearest to the eye where a person uses maximum convergence but still his retina got clear image of an object.

Raf rule is used to measure the near point of convergence.
Requirements :
1.Normal illuminated room
2.RAF rule
3.adjustable chair for examiner and patient
4.page and pen

Procedure:
The cheek pad should be placed on the inferior orbital margin of the patient and for better result the position of the RAF rule should be slightly depressed at 45°.
The standard target which is used for measuring Near point of convergence is Dot on vertical line target.
The target should be moved towards the patient eye with linear and constant speed of 1 to 2 centimeter per second.
Keep moving the dot target towards the patient eyes and instruct the patient to stop when the target point gets double.
The point where the target dot get double that point is called BREAK POINT, because the fusion of both eyes break at that point.
Now move the target dot back and instruct the patient to inform when the target again get clear and single.
The point where the target point again get single is called RECOVERY POINT.
and this recovery point is actually the NEAR POINT OF CONVERGENCE.
Record the value in centimeter scale and also in CONVERGENCE SCALE... whether the convergence is NORMAL, REDUCED OF DEFECTIVE.