NEAR POINT OF CONVERGENCE EQUIPMENT NEEDED Penlight Gulden fixation stick Red/green glasses  SETUP 1. If the patient wears glasses for close work, these should be used.  2. Hold Gulden fixation stick tongue depressor 40 cm from patient’s face at eye level. 3. Ask the patient to look at the isolated 20/50 target on the Gulden fixation stick. PROCEDURE 1. Slowly move the fixation stick toward the patient at eye level and between the two eyes.  2. Ask the patient to keep the target one for as long as possible.  3. Ask the patient to tell you when he or she sees two targets ..read more

  AC/A Ratio Measurement Using the Modified Thorington Test   EQUIPMENT NEEDED         Penlight          Maddox rod         Thorington card SETUP         The patient should wear his or her distance glasses.         The patient holds the Maddox rod before the right eye, with the striations of the Maddox rod oriented horizontally (patient sees red vertical streak of light).         Hold the Thorington card at 40 cm with a penlight b ..read more

STEREOPSIS EQUIPMENT NEEDED         Randot stereopsis test        Polaroid glasses   SETUP         The patient should wear Polaroid glasses over his or her appropriate prescription.         The plates should be well illuminated, glare free, and upright to ensure proper axis of polarization.         Do not allow the patient to do any head tilting or turning   PROCEDURE         The test plates are presented in order, at 40 cm.   ..read more

 Worth Four-dot Test EQUIPMENT NEEDED     Worth four-dot flashlight Red/green glasses SETUP  The patient should be wearing red/green glasses and distance correction in place  Hold the Worth four-dot flashlight at 33 cm.  PROCEDURE          Cover the patient’s left eye and ask, “How many lights do you see?”          Now cover the left eye and ask, “How many lights do you see?”         Now with both eyes open ask, “How many lights do you see?”          R ..read more

 Worth Four-dot Test Purpose • Subjective test designed to evaluate the presence and size of the suppression scotoma • one of the most accurate methods of evaluating suppression Important issues 1. Determining the size of the suppression scotoma • The size of the suppression scotoma can be determined by moving the Worth four-dot flashlight away from the patient. • As the flashlight is moved away from the patient, the target subtends a smaller angle. • For instance, at 33 cm, the target subtends an angle of approximately 4.5 degrees. • At 1 m, the angle subtended is approximately 1.5 ..read more

Purpose • Objective method • Evaluating the presence, direction, and the magnitude the phoria Important issues  Controlling accommodation • Accommodative system as a potential source of variability in clinical heterophoria measurement. • Underaccommodation will result in an overestimation of the degree of exophoria • Underestimation of the esophoria. • Overaccommodation will yield the opposite results.  Objectivity • An objective technique • Assessing the motor characteristics of binocularity. • Valuable when working with young children  Repeatability • Alternate cover test with prism ne ..read more

  Cover  Test Purpose• Objective method • Evaluating the presence, direction, and the magnitude the phoria Important issues Controlling accommodation • Accommodative system as a potential source of variability in clinical heterophoria measurement. • Underaccommodation will result in an overestimation of the degree of exophoria • Underestimation of the esophoria. • Overaccommodation will yield the opposite results.  Objectivity• An objective technique • Assessing the motor characteristics of binocularity. • Valuable when working with young children  Repeatability • Alternate ..read more

 Important steps in evaluation of Binocular Vision  1 2.  3. 4 ..read more

 Esophoria at Distance: Convergence Excess • Patient who has a low to moderate degree of esophoria at distance (high tonic vergence) • High AC/A ratio • Degree of esophoria at near will be significantly greater than that at distance Characteristics Symptoms All of the following are associated with reading or other near tasks: • Asthenopia and headaches • Intermittent blur • Intermittent diplopia • Symptoms worse at end of day • Burning and tearing • Inability to sustain and concentrate • Words move on the page • Sleepiness when reading • Decreased reading comprehension over time • Slow r ..read more

 Exophoria at Distance: Divergence Excess • Patient who has a low to moderate degree of exophoria at distance (low tonic vergence) • High AC/A ratio. • Degree of exophoria at near will be significantly less than that at distance Characteristics Symptoms• Parents complain of eye turning out • Occasional near point asthenopia • Child closes one eye in bright light. Signs • Greater exophoria or intermittent exotropia at distance than at near • High calculated AC/A ratio • Suppression at distance • Normal near point of convergence • Limited NFV, adequate PFV • Difficulty with first- and s ..read more