Optometric measurement standards

Determination of Visual refractive errors of the nature, degree and axial method. Subjective optometry optometry and objective is divided into two kinds: ① subjective optometry, optometry. Mainly by checking your own subjective feelings to determine the refractive error of the nature and extent of eye lens in the regulating State in front of patients, according to the vision of progress and decided to appropriate lenses. First try the lenses. Only with a ball lens vision correction lenses not satisfied can add columns, and rotate the cylinder to determine the axial and degrees, to vision correction are satisfied. II objective refraction law, also known as the Optometry Act. Check Qian with ciliary muscle paralysis drug bulk pupil, in darkroom in the, check who and patients relative and sat, apart 1 meters, told patients watched are ahead, check who back and forth shake check shadow mirror, observation pupil Central light of form, and brightness, and mobile speed and and check shadow mirror swing direction of relationship, dang shadow moving and mirror moving direction consistent Shi for Shun moving, to convex ball mirror correction of. Conversely, if a reversal, with concave lenses to correct until the lights do not move so far. Retinoscopy with movement, you may to the hyperopia, myopia of -1.0D or less squarely, as for reversal is myopia greater than-1.0D, such as fixed or -1.0D for myopia. Light in the large round simple farsightedness or nearsightedness, such as rendering a band is astigmatism. Astigmatism with Shun moving who, with convex ball lenses or convex column lenses correction, astigmatism with for inverse moving who to concave ball or concave column lenses correction, column lenses of axis to and astigmatism with of direction consistent, this that for astigmatism of axis to, in 1 meters at check shadow equivalent diopter for -1.0D, it and check shadow proceeds diopter of algebra and that infestation eye of actual diopter.