Show testing tta T t A the eye I 1 lecturing ruling on ad the effect OR OB the era BA of V varying degrees degree of brightness and contrast before the illuminating Ud AdUM ed 0 earing society recently rally dr james kerr rc of 1 the public bee health department of the ill london county COB oty coun Is 11 referred to borne a effects effect which bach may A be surprising A art 1 9 having to examine long ions list hats of figures I 1 in black type he be tried to ta fe his task by drawing vertical and ad borbon horizontal ted I 1 lines nee in rod red ink bals but thal ill different foe of the black bud and red strained truit ard hia eye and gave him a headache which marh did not trouble him when oil nil tho the figures ft game nna and lines were either black or red doctor kerr q anes tlona tied whether a target la is more distinct 1 alien A hen a ft Y gilleand bial disk op pears peara on a jet black background than 0 when he ill the ad were A aff diffusely illuminated |