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1、柱面透镜的识别与中和,1、视觉像移 如何操作？ 顺动表明什么，逆动表明什么？ 轴向如何定？,2、旋转实验 柱面镜片的鉴别：旋转实验不产生剪刀运动的镜片无柱镜成分，产生剪刀运动的有柱镜成分 在旋转试验里如何判断逆剪刀运动还是顺剪刀运动？要注意什么问题？,操作2 旋转试验,剪刀运动,正柱镜，逆剪刀,负柱镜 顺剪刀,要注意：轴向要与垂直线平行。 旋转实验：剪刀运动，正镜逆剪刀运动 负镜顺剪刀运动 思考：如轴向与水平线平行可以吗？,旋转试验的运用,鉴定球面还是柱面 确定柱镜的主子午线,Action of a plus cylinder,This is a crossline chart. On the
2、 next mouse click you will place a plus cylinder held with its axis VERTICAL in front of the chart,Notice that the limbs appear to be in their original positions but that just the vertical limb is magnified in the horizontal meridian.,On clockwise rotation of the cylinder, the vertical limb rotates
3、anticlockwise and the horizontal limb rotates clockwise towards it in a SCISSORS MOVEMENT.,Further clockwise rotation of the cylinder, produces further SCISSORS MOVEMENT.,Rotating the cylinder back again causes the limbs to, SCISSOR back to their original position. You can emulate the actual movemen
4、t seen during the rotation test by RIGHT clicking four times back through this sequence.,The cylinder axis can be marked on the lens when it has been rotated to this position where a continuous appearance of the crosslines is obtained.,On the next mouse click you will place a minus cylinder held wit
5、h its axis VERTICAL in front of the chart,Notice that the limbs appear to be in their original positions but that just the vertical limb appears minified in the horizontal meridian.,Action of a minus cylinder,On clockwise rotation of the cylinder, the vertical limb also rotates clockwise and the hor
6、izontal limb rotates anticlockwise towards it in a SCISSORS MOVEMENT.,Further clockwise rotation of the cylinder, produces further SCISSORS MOVEMENT.,Rotating the cylinder back again causes the limbs to, SCISSOR back to their original position. You can emulate the actual movement seen during the rot
7、ation test by RIGHT clicking four times back through this sequence.,The cylinder axis can be marked on the lens when it has been rotated to this position where a continuous appearance of the crosslines is obtained.,Ophthalmic Lenses & Dispensing,圆柱面透镜的鉴别与测量,圆柱面镜片的鉴别：旋转实验不产生剪刀运动的镜片无柱镜成分，产生剪刀运动的有柱镜成分。
8、,中和法测量柱镜度数步骤,视觉像移及旋转实验判断性质和轴向 取性质相反负镜片与待测镜片叠合，注意两镜片轴向一致，光心相重,持叠合镜片再次做旋转实验，根据结果调换镜片，直至没有剪刀运动 根据已知镜片记录未知镜片,柱面透镜的联合,联合符号有两种：“ ” 和 “ / ” 联合形式有三种：同轴，正交、斜交 用光学十字图表示柱镜组合更简单。,光学十字如何表示,+2.00 X 180,- 2.00 X 90,轴向相同的两圆柱面透镜，叠合后其轴向不变，其镜度为两圆柱面透镜镜度之和 例：+1.00DC180 +2.00DC180 =+3.00DC180,两轴向相同，镜度相反的圆柱面透镜叠合后不再有镜度，其光学
9、效果等效于平行玻璃板 +3.00DC180 -3.00DC180=0,+3.00DC,0,+,=,0.00DC,0,如果轴向相互垂直，结果怎样？,光学十字,+3.00 X 180,- 3.00 X 90,两轴互相垂直，镜度相同的圆柱面透镜叠合，其效果等于一个球面透镜，此球镜的镜度与两柱面透镜镜度相同。 +3.00DC180 +3.00DC90=+3.00DS,+3.00DC,0,+,=,一个柱面镜可由一相同镜度的球面镜和一个镜度相同但符号相反且轴向垂直的柱镜所叠加 +3.00DC90=+3.00DS -3.00DC180,=,-3.00DC,0,+,光学十字(2),+2.00 X 180,-
10、6.00 X 90,两轴互相垂直，镜度不同的圆柱面透镜叠合，其效果相当于一个球镜加一个柱镜 +1.00DC90 +3.00DC180 =+1.00DS/+2.00DC180 =+3.00DS/-2.00DC90,0,+3.00DC,0,+,+1.00DC,=,+3.00DC,+1.00DC,+1.00DC,+2.00DC,+3.00DC,-2.00DC,例题练习： +1.00DC90 -3.00DC180 =+1.00DS/-4.00DC180 =-3.00DS/+4.00DC90,0,-3.00DC,0,+,+1.00DC,=,-3.00DC,+1.00DC,+1.00DC,-4.00DC,
11、-3.00DC,+4.00DC,例题练习： +4.00DC90 / -1.00DC180 -1.00DC180 / -4.00DC90 -3.00DC90 / +4.00DC180,两柱镜正交叠合而成的球镜加柱镜有两种形式：一为球镜加正柱镜；另一为球镜加负柱镜，两种形式的光学效果完全相同,+1.00DC90+3.00DC180 =+1.00DS/+2.00DC180 =+3.00DS/-2.00DC90,转换规则：已知两轴向互相垂直的圆柱面透镜的镜度分别为F1、F2，则叠合后 1、以F1为球镜镜度，（F2-F1）为柱镜镜度， 柱镜轴向与镜度为F2的柱镜相同 2、以F2为球镜镜度，（F1-F2）
12、为柱镜镜度， 柱镜轴向与镜度为F1的柱镜相同,+1.00DC90+3.00DC180 =+1.00DS/+2.00DC180 =+3.00DS/-2.00DC90,2密接斜交柱镜的联合,2柱镜斜交，联合后必有一个方向镜度最小，该方向应该在2柱镜的轴之间，而与之垂直的方向镜度最大。,2柱镜以任何角度相加，等效于一球面加一新柱面。 设相加后球镜度数为S，柱镜度数为C 计算公式。,正切公式法 运算步骤 1、将2柱镜转为正柱镜 2、将柱轴方向较小者定位F1 3、 a=F1的轴-F2轴 4、分别代入公式算出球柱镜度数及角 5、将加于F1的轴向即为新柱镜轴向,汤普森公式法,公式。 例题。,作图法,画平行四边形后其对角线代表叠加后的柱镜度 测量对角线与F1的夹角再将其除以2为柱镜轴方向与F1的轴向的夹角,作业：课后思考题,