视直径

当日心角增大时，黑子的视直径下降得比由几何缩减所予期的要快些。

When θ increases , the apparent diameter of the spot decreases faster than would be expected from geometric foreshortening .

不，当地球与火星绕著太阳运行时，由地球上看火星的视直径会不断地改变。

As both Earth and Mars orbit the Sun , the apparent angular size of Mars changes as viewed from the Earth .

低、中度近视组平均暗视瞳孔直径（6.24±0.72）mm；

The scotopic pupil sizes in low , moderate myopia group was 6.24 ± 0.72 mm ;

应用活组织显微镜和78D透镜测量视乳头直径的初步研究

A preliminary study of the measurement of optic disc diameter with 78 D lens and biomicroscope

视区切削直径大小对LASIK手术患者波前像差的影响

Effect of the size of ablation zone on the wavefront aberration in the LASIK patients

目的采用MRI在活体上测量各段视神经的直径和探讨显示视神经全程的最佳MRI扫描基线。

Objective To measure diameter of normal human optic nerve in vivo on MR imaging and search for the optimal scanning baseline displaying the whole optic nerve .

目的：研究视区切削直径大小对LASIK手术后患者波前像差的影响，以便指导临床LASIK手术方式的选择。

· AIM : To study the effect of the size of ablation zone on the wavefront aberrations in the LASIK operations .

视标面积的直径大小也有1.5mm、8mm、14mm三个水平。

The area of the signals were classified into three levels by diameter : 1.5 ? millimeter , 8 millimeter and 14 millimeter .

将钢丝软轴视为由许多不同直径的圆柱螺旋钢丝叠套在一起组成的弹簧钢丝簇。

Flexible shaft with its wire may be considered as helical wire cluster composed of a number of different diameters cylinder helical steel wire .

这些记录可以按古人目视观测天象的天球模型进行视大小（角直径）的量化，进而可以用一些已知亮度的流星记录为标准点，将其归算为亮度。

These records can be quantified to apparent scales ( angular diameter ) according to the Model of Celestial Sphere used by Chinese ancients . Then we can reduce the size to a brightness on the basis of some " standard points " .

目的：评价正常成人视神经、视神经蛛网膜下腔的MRI表现；通过测量视神经直径和蛛网膜下腔外径，建立正常标准。

Objective : To evaluate the MRI features of optic nerve and subarachnoid space in the normal adults and to establish the normal standards of them by measurement on MRI .