Refraction procedures

Refraction procedures

Refraction procedures, such as retinoscopy and subjective refraction, are performed in order to determine the best refractive correction for each eye independently and, where appropriate, when the patient is binocular.

Refraction procedures
  • R001 Retinoscopy : an objective technique for assessment of refractive error

    Retinoscopy can provide an approximation of refractive error and this is useful in cases where the patient finds it difficult to communicate, new patients who have not brought their glasses to the consultation and those who have not had previous refractive correction. The power of the trial lense...

  • R001-Spot-retinoscopy.pdf

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  • R002 Mohindra technique - near fixation retinoscopy

    There are some potential adverse reactions, side effects and legal issues in the use of cycloplegic drugs. Alternatives to using drugs have been suggested. One such method is near fixation retinoscopy-often referred to as the Mohindra technique. This relies on the fact that young children are lik...

  • R002-Near-fixation-retinoscopy-(Mohindra-technique).pdf

    99.5 KB

  • R003 Jackson cross-cyl-accurate determination of astigmatic refractive error

    Because of errors arising from working off the visual axis and spherical aberration during retinoscopy, before a prescription can be issued the results obtained need to be refined during subjective refraction. The Jackson cross-cylinder is used to refine the correction for astigmatism.

  • R003-Jackson-cross-cylinder-(JCC).pdf

    94.6 KB

  • R004 Binocular balancing

    Following retinoscopy and subjective refraction, binocular balancing is used to ensure that the accommodation is balanced in each eye. It corrects any extra hyperopia that may become manifest when the patient becomes binocular. Binocular balancing ensures that accommodation is balanced between th...

  • R004-Binocular-balancing.pdf

    70.5 KB

  • R005 Binocular addition

    Accommodation relaxes in binocular single vision and therefore binocular addition may not be necessary as balancing with monocular fogging may have already relaxed accommodation maximally. However, binocular addition can be used as a final check to ensure that the accommodation is completely rela...

  • R005-Binocular-addition.pdf

    62.3 KB

  • R006 Determination of near add.

    Presbyopia is a refractive condition in which the accommodative ability of the eye is insufficient for near vision work. It usually occurs at 40-45 years of age but may be earlier in people living in hot climates, people with short arms/working distances and hyperopes and later in people with lon...

  • R006-Determination-of-the-near-add.pdf

    89.9 KB