視光部分ICO復(fù)習(xí)課件

1、視光部份ICO復(fù)習(xí)相對(duì)調(diào)節(jié)負(fù)相對(duì)調(diào)節(jié)：能放松的調(diào)節(jié)，加正鏡。正相對(duì)調(diào)節(jié)：能做出的最大調(diào)節(jié)量，加負(fù)鏡。根據(jù)Hofstentters公式： 最小調(diào)節(jié)幅度15-0.25年齡 平均調(diào)節(jié)幅度18.5-0.3年齡 最大調(diào)節(jié)幅度25-0.4年齡Accommodationa) myopic patients may increase their myopic prescription and avoid the wear of reading glassesb) the near point of an emmetropic patient who has 5D of accommodative power

2、is 20cmc) in order to focus at an object placed at 20cm, a patient with myopia of -2.00D requires an accommodative power of 2Dd) myopia can be partially overcome by accommodatione) an emmetropic patient with 2D of accommodative power can read comfortably at 33cm without reading glasses球柱鏡轉(zhuǎn)化記住原則：球柱相加

3、為新球鏡，柱鏡度數(shù)不變，柱鏡交換符號(hào)，軸位旋轉(zhuǎn)90（大于90的減去90小于90的加上90。）順歸性散光（with the rule ，WR）：角膜高屈光力子午線位于垂直位（12060）逆規(guī)性散光（AR）：角膜高屈光力子午線位于水平位（15030）斜軸散光：角膜高屈光力子午線位于3060或是120150Jackson cross-cylindera) a -0.50D sphere is coupled with a -1.00D cylinderb) is useful in refining the spherical power during trial of lensc) the han

4、dle is mounted parallel to one of the axes of the cylindersd) when refining the power of a trial cylinder, the handle of the Jackson cross-cylinder is placed in line with the axis of the trial cylindere) a Jackson cross-cylinder designated 1.00D consists of a +1.00D cylinderTransposition of cylinder

5、sa)-4.00DS/-1.00DC170= -5.00DS/+1.00DC170b)+2.00 DS/+1.00DC150= +1.50DS/-1.00DC130c)-1.00 DS/+2.00DC100= +1.50DS/+1.00DC10d)-3.00 DS/+1.00DC150= -2.00DS/-1.00DC60e) -1.00 DS/-2.00DC180= +1.00DS/+2.00DC90立體視正常立體視覺(jué)60seconds or better，單位seconds,提示可能存在弱視：低于250seconds。立體視圖譜檢查： TNO：紅綠眼鏡 480-15 seconds TIM

6、US TEST（包括wirt fly）：偏振眼鏡 3000-40 seconds FRISBY：不需眼鏡 600-15seconds棱鏡棱鏡處方：內(nèi)斜底朝外，外斜底朝內(nèi)水平斜棱鏡度分配到雙眼，棱鏡底朝向相同，上下斜棱鏡分配到雙眼時(shí)方向相反。光線折射后朝棱鏡底部偏移，D偏移角=棱鏡頂角/2在距離棱鏡1m處，如果折射光線與入射光線發(fā)生偏折1cm，則為1棱鏡度。1度等同于1.75棱鏡度。 1棱鏡度等同于0.5729度。 散光的軸采用的是0-180度，而棱鏡采用0-360度。 計(jì)算球面透鏡移心后的棱鏡效果公式： PcF C:入射點(diǎn)到光心的距離 ，單位cm F：透鏡的屈光度光譜UV-C 200-280n

7、m，UV-B 280-315,UV-A 315-400 可見光400-780nm Infrared A 780-1400nmInfrared B 1400-3000nmInfrared C 3000-10000nm色像差：應(yīng)用于驗(yàn)光雙色試驗(yàn)：確保近視者不過(guò)矯，對(duì)0.25D差別敏感，紅綠色盲者也適用。原理：紅波波長(zhǎng)長(zhǎng)折射率小，綠波的波長(zhǎng)短折射率大，所以綠色背景上的視標(biāo)所成的像較紅色的所成的像更靠近角膜些。結(jié)果：紅色背景清，應(yīng)減少正鏡（或增加負(fù)鏡）；綠色清應(yīng)增加正鏡（或減少負(fù)鏡），近視者綠清為過(guò)矯了。Duochrome testa) is useful in myopic patients to

8、avoid undercorrectionb) cannot be used in colour blind patientsc) is due to spherical aberration of the eyed) red light is refracted less than green lighte) at completion of duochrome test, green letters should be clearer than red letters檢影中和點(diǎn)的判斷：越接近中和光影越亮，運(yùn)動(dòng)越快，光帶越大。馬式桿：右眼放馬式桿，桿在水平位成像為垂直的線條。 記住內(nèi)同外交。（內(nèi)斜線條與馬式桿同側(cè)，外斜交叉。） 遠(yuǎn)視患兒內(nèi)斜內(nèi)隱斜盡量足矯（放松調(diào)節(jié)），近視患兒外斜外隱斜（