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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)
Presbyopia is a typical part of the aging process. [4] It occurs due to age related changes in the lens (decreased elasticity and increased hardness) and ciliary muscle (decreased strength and ability to move the lens), causing the eye to focus right behind rather than on the retina when looking at close objects. [4]
In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak ...
The formula may appear simpler in terms of renamed simple values = / and =, avoiding any appearance of trig function names or angle names: v → r e f r a c t = r l → + ( r c − 1 − r 2 ( 1 − c 2 ) ) n → {\displaystyle {\vec {v}}_{\mathrm {refract} }=r{\vec {l}}+\left(rc-{\sqrt {1-r^{2}\left(1-c^{2}\right)}}\right){\vec {n}}}
Cauchy's two-term equation for air, expanded by Lorentz to account for humidity, is as follows: n a i r ( λ , T , v , p ) ≈ 1 + 77.6 ⋅ 10 − 6 T ( 1 + 7.52 ⋅ 10 − 3 λ 2 ) ( p + 4810 v T ) {\displaystyle n_{air}(\lambda ,T,v,p)\approx 1+{\frac {77.6\cdot 10^{-6}}{T}}\left(1+{\frac {7.52\cdot 10^{-3}}{\lambda ^{2}}}\right)\left(p+4810 ...
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.
If the single prism is a right-angled prism with the beam exiting normal to the output face, that is , equal to zero, this equation reduces to ( ∂ ϕ 2 , 1 / ∂ λ ) = t a n ψ 1 , 1 ( ∂ n 1 / ∂ λ ) {\displaystyle (\partial \phi _{2,1}/\partial \lambda )=tan\psi _{1,1}(\partial n_{1}/\partial \lambda )}
Ericson-Ericson Lorentz-Lorenz correction. Ericson-Ericson Lorentz-Lorenz correction, also called the Ericson-Ericson Lorentz-Lorenz effect (EELL), refers to an analogy in the interface between nuclear, atomic and particle physics, which in its simplest form corresponds to the well known Lorentz-Lorenz equation (also referred to as the Clausius ...
If the eye was exotropic, covering the fixating eye will cause an inwards movement; and if esotropic, covering the fixating eye will cause an outwards movement. The alternating cover test, or cross cover test is used to detect total deviation (tropia + phoria).
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