Having determined the refraction of the right and left eye separately under monocular conditions, it is important to ensure that these refractions correspond well under binocular conditions. The spherical component is adjusted as necessary to equalize the accommodative effort of the two eyes.
Note that most binocular balance techniques can be performed only when the patient has equal visual acuity in both eyes
5-6 pd base up in front of OD os od e x o e s o orto Prism Light source
Polarized cross test Polarized glases + distance polarized test Helps to evaluate phoria. Depending on the test conditions (type of dissociation) the phoria will be said to be associated or dissociated. Whether the test used involves the an element of fusion, perceived in common by both eyes or not.
- bring the test closer to the patient until the smallest characters are no longer able to be seen clearly. This should occur at approximately 25 cm from the eyes (if < 20 cm, the addition is too strong, if > 30 cm the addition is too weak.)
- adjust the value of addition (from 0,25D to 0,50 D) in accordance with required working or reading distance. If different from 40 cm at which the test was conducted. Reduce the addition for longer working distance, increase for shorter working distance.