Jennifer S. Simonson, OD, FCOVD
Boulder Valley Vision Therapy
1790 30th Street, Suite 311, Boulder, CO 80301
(303) 443-2257 (303) 443-4599 (FAX)
Valenti Crossed Cylinder Rock Technique
Purpose: To gain control of stimulating and inhibiting accommodation independently of vergence and vice versa. This is a biofeedback technique that brings to the individual’s conscious awareness and trains control of: the relative amount and direction of accommodation; the relative amount and direction of vergence; the relative degree of accommodation independent of vergence; and the relative degree of vergence independent of accommodation.
Equipment: Crossed cylinder lenses with a dissociating prism; standard crossed cylinder grid (a series of vertical and horizontal lines crossing at right angles on s clear white background); the standard cylindrical lenses are +1.00 x 180 and -1.00 x 90 with a prism in the range of 6 to 9 diopters.
The target should be 16 inches from the patient’s eyes.
When the patient looks at the target s/he should report the following:
two crossed cylinder targets (one target is seen by each eye);
the vertical or horizontal lines blacker, or equality of blackness between horizontal and vertical lines. This is dependent upon the patient’s accommodative response;
the top target to the left, in line with, or to the right of the bottom target. This is dependent upon the patient’s vergence response.
3. Can you do something differently to change how things look.
1. If accommodation is at the plane of the target, both vertical and horizontal lines will be equally black.
2. If accommodation is in front of the target the vertical lines will be blacker.
3. If accommodation is behind the target, the horizontal lines will be blacker.
1. If converged equal to the target, both crossed cylinder targets will be in vertical alignment.
2. If convergence is closer than the target, the top target will appear to be to the right.
3. If convergence is beyond the target, the top target will appear to be to the left of the bottom target.
1. Adjust accommodation (shift horizontal and vertical lines as blacker) without affecting the vergence system (without shifting the position of the top target relative to the bottom target).
2. Flex the vergence system (move the top target to the right and left of the bottom target) without affecting the accommodative system (without shifting horizontal or vertical lines blacker).
Aspects to emphasize: The key to improvement, as with all biofeedback techniques, is in making the individual aware of that which s/he is otherwise unaware and to internally discover new means of control. The crossed cylinders allow the individual to be aware of both speed and direction of the accommodative response. There is a neurological independence between the autonomic nervous system (accommodation) and the somatic nervous system (convergence). The individual must then learn to associate what s/he is doing (how s/he is thinking, feeling, what s/he is attending to, where and how s/he is looking) with her/his visual behavior.
Modifications: Move the target closer and further as needed. As eye control improves, keep at a set distance.
Category: Focus and Vergence Skill date modified: 2//12