Unitech Vision - Testing Equipment

Cross cylinder examination (otherwise known as Jackson's cross cylinder) is an examination used for the final fine-tuning of the axis and strength of astigmatism after its determination through retinoscopy, stellate cycle or automatic refractometry. With the advent of technology, techniques like retinoscopy and cross cylinder examination might seem outdated and useful only to the personnel of humanitarian missions. They do however provide an accurate alternative and their use gives a thorough understanding of the principles of refraction.

The major components of the phoropter are the battery of spherical and cylindrical lenses, auxiliary devices such as Maddox rods, filtered lenses, prisms, and the JCC (Jackson Cross-Cylinder) used for astigmatism measurement. Theprismaticlenses are used to analyze binocular vision and treatorthopticproblems.

From the measurements taken, the specialist will write aneyeglass prescriptionthat contains at least 3 numerical specifications for each eye: sphere, cylinder, and axis, as well aspupillary distance(distance between eyes), and, rarely, prism for one or both eyes.

Chart distance available:

6 feet, 8 feet, 12 feet, 15feet, 20 feet, and mirror charts. All distance charts in built with machine

Monitor size:18.5 inch (wide)

Eye education chart:

Cataract, retina, cornea, glaucoma, lasik, contact lens ( total 100 charts)

Voltage: 110/230V /50 or 60Hz; weight: 3 kg net

Brock Strings consist of a white nylon string 10 or 12 feet in length with three (3) small wooden beads of different colors. Alternate models are 6 or 12 ft with 5 beads. They are used for treatment of convergence insufficiency and other anomalies of binocular vision as well as to disrupt suppression. During therapy, the end with the stick is held near the tip of the nose while the other end with the loop is hung to a fixed point like a door knob.