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Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: = where: P is the amount of prism correction (in prism dioptres) c is decentration (the distance between the pupil centre and the lens's optical centre, in millimetres)
The formula for vertex correction is = (), where F c is the power corrected for vertex distance, F is the original lens power, and x is the change in vertex distance in meters.
To make the linear dispersion of the system zero, the system must satisfy the equations 1 f 1 + 1 f 2 = 1 f d b l t , 1 f 1 V 1 + 1 f 2 V 2 = 0 ; {\displaystyle {\begin{aligned}{\frac {1}{\ f_{1}\ }}+{\frac {1}{\ f_{2}\ }}&={\frac {1}{\ f_{\mathsf {dblt}}\ }}\ ,\\{\frac {1}{\ f_{1}\ V_{1}\ }}+{\frac {1}{\ f_{2}\ V_{2}\ }}&=0\ ;\end{aligned}}}
Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.
Description. Mathematically, such a calculation can be expressed: The bolometric correction for a range of stars with different spectral types and groups is shown in the following table: [1] [2] [3] The bolometric correction is large and negative both for early type (hot) stars and for late type (cool) stars.
Maddox wing. The Maddox Wing is an instrument utilized by ophthalmologists, orthoptists and optometrists in the measurement of strabismus (misalignment of the eyes; commonly referred to as a squint or lazy eye by the lay person). It is a quantitative and subjective method of measuring the size of a strabismic deviation by dissociation of the ...
Example 1 Consider the function f : R 2 → R 2 , with ( x , y ) ↦ ( f 1 ( x , y ), f 2 ( x , y )), given by f ( [ x y ] ) = [ f 1 ( x , y ) f 2 ( x , y ) ] = [ x 2 y 5 x + sin y ] . {\displaystyle \mathbf {f} \left({\begin{bmatrix}x\\y\end{bmatrix}}\right)={\begin{bmatrix}f_{1}(x,y)\\f_{2}(x,y)\end{bmatrix}}={\begin{bmatrix}x^{2}y\\5x ...
Then iteratively evaluate the following equations until λ converges: sin σ = ( cos U 2 sin λ ) 2 + ( cos U 1 sin U 2 − sin U 1 cos U 2 cos λ ) 2 {\displaystyle \sin \sigma ={\sqrt {\left(\cos U_{2}\sin \lambda \right)^{2}+\left(\cos U_{1}\sin U_{2}-\sin U_{1}\cos U_{2}\cos \lambda \right)^{2}}}}
This formula for Q arises from applying best linear unbiased estimation to a linearized version of the sensor measurement residual equations about the current solution _ = (()), except in the case of B.L.U.E. is a noise covariance matrix rather than the noise correlation matrix used in DOP, and the reason DOP makes this substitution is to ...
One model for this relationship is the Colebrook equation (which is an implicit equation in ): 1 f D = − 2.0 log 10 ( ϵ / D 3.7 + 2.51 R e f D ) , for turbulent flow . {\displaystyle {1 \over {\sqrt {f_{D}}}}=-2.0\log _{10}\left({\frac {\epsilon /D}{3.7}}+{\frac {2.51}{\mathrm {Re} {\sqrt {f_{D}}}}}\right),{\text{for turbulent flow}}.}