. Manual of mental and physical tests : in two parts : a book of directions compiled with special reference to the experimental study of children in the laboratory or classroom. 17 may be added. A. TEST FOR MYOPIA AND HYPEROPIA Apparatus.—Lowells test-type. Trial frame (Fig. 35). Two—.75 and two + -75 D. spherical lenses, and one blank stick. ^he McCallie cards, purchasable of Edwin Fitzgeorge, Box 67, Tren-ton, N. J., are well adapted for rapid schoolroom tests, where the methodof distance alone is used and no direct attempt is made to detect hyper-opia or astigmatism. The illi
. Manual of mental and physical tests : in two parts : a book of directions compiled with special reference to the experimental study of children in the laboratory or classroom. 17 may be added. A. TEST FOR MYOPIA AND HYPEROPIA Apparatus.—Lowells test-type. Trial frame (Fig. 35). Two—.75 and two + -75 D. spherical lenses, and one blank stick. ^he McCallie cards, purchasable of Edwin Fitzgeorge, Box 67, Tren-ton, N. J., are well adapted for rapid schoolroom tests, where the methodof distance alone is used and no direct attempt is made to detect hyper-opia or astigmatism. The illiterate set is especially ingenious. *One diopter, or dioptric, D, is the amount of refraction given by alens whose principal focal distance is 1 XQcter, i. e., the radius of curva-ture of its surface has a length of 1 meter. This unit is nov/ commonlyused in place of the older systoni of indicating strength in incJies of focallength. TEST 14: VISUAL ACUITY 167 Preliminaries.—Place the test type on the wall or stand, ona level with >S^^s eyes, in a strong even illumination, though notin actual sun-light.^ Seat S conifoitnbly at a distance of 6 m.,from the MG. 35. ^rillAL FRAME. Holds two pairs of lenses, and has rack and pinion adjustment forpupillary distance, and for vertical, and back and forward movement ofthe nosepiece. Note any indication of soreness or inflammation of the eyes,lids, or conjunctiva. Ascertain if S has ever suffered from suchinflammations, from habitual headaches, or watery eyes;whether his eyes become painful, sore, or strained in doing closework; whether he has previously been examined, and if so, withwhat result; whether he has ever worn glasses; if they have If conditions render dayliglit illumination unreliable or unsatisfac-tory, E must arrange artificial illumination, carefully shaded from devices for this purpose may be purchased from dealers inoptical supplies, c. g., No. 4274, cataloj, of E. B. Meyrowitz. New YorkCity,
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Keywords: ., boo, bookcentury1900, bookdecade1920, booksubjectpsychophysiology
