Subjective refraction is achieved by meticulous refinement of reliable, objective cycloplegic and manifest refractions. It is especially important in patients with high astigmatism, allowing determination of the maximum amount of tolerable astigmatic correction to be performed by refractive surgery. The end point is the least amount of minus correction that results in the greatest resolution. The Jackson cross cylinder and the duochrome test are valuable adjuncts. Subjective autorefractors are simple enough to be used by technicians with a moderate degree of training and serve as a complement to subjective refraction. They are reliable and accurate, but binocular balance and near-point testing are best performed using conventional refraction.5
Measurement of the amplitude of accommodation is an important component of the diagnostic workup of refractive surgery candidates. Decreased accommodative reserve in patients with hyperopia may lead to early presbyopia. Loss of the near effectivity of minus spectacles in myopes after refractive surgery may worsen near vision and require reading spectacles, which may decrease patients’ satisfaction.