Evans Freeman Near Vision Unit

Description

Evans Freeman Near Vision Unit

• Freeman Near Vision Unit
• The NVU provides a complete subjective means of investigating the Near Vision refraction.
• The general appearance of the unit can be seen in the illustration.
• It is in the form of a three side drum which is LED illuminated.
• It can be held by the patient or suspended by means of a special attachment from the rod of a Refactor Head.
• The unit should be used in a room moderately lit, or with external illumination from an ordinary reading lamp.

• Side One – The Vocational Acuity Chart
  The reading matter of this test is in 4 sizes of Times Roman type face, the smallest being 5 pt.
• When read aloud by the patient it gives them useful information as to their standard of reading vision and what it corresponds to in every day printed matter.
• Side Two – The Binocular Bichromatic Chart
  In addition to red and green filters this chart is fitted with Polarised screens.
• Used without a polarising visor this chart immediately reveals accommodation insufficiency and the chromatic balancing allows the correction of presbyopia for any working distance.
• Used with the visor it is possible to check one eye against the other, then balancing the accommodation for right and left.
• Side Three – The Oblique Tangent Scale
  The scale shows 14 degrees of Exophoria and 7 degrees of Esophoria in red colour.
• It provides in conjunction with the green Maddox Twirl a rapid measurement of horizontal and vertical muscle imbalances.
• The Clinical Acuity Chart
  This consists of a matched pair of Landolt rings graduated in size.
• Accurate measurement of near astigmatism can be made with cross Cylinders.
• The Near Prism indicator
  The targets, which consist of two dots placed horizontally and two arrows placed vertically about a central fixation cross, are polarised as well as being fitted with a red and green fixers.
• They can therefore be separated for right to left eyes either with a polarizing visor, red/green goggles or hand frame

code 661