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Amblyopia. Anisometropia is a condition in which a person's eyes have substantially differing refractive power. [1] Generally, a difference in power of one diopter (1D) is the threshold for diagnosis of the condition . [2] [3] Patients may have up to 3D of anisometropia before the condition becomes clinically significant due to headache, eye ...
A prism of power 1 Δ would produce 1 unit of displacement for an object held 100 units from the prism. Thus a prism of 1 Δ would produce 1 cm visible displacement at 100 cm, or 1 meter. This can be represented mathematically as: = where is the amount of prism correction in prism dioptres, and is the angle of deviation of the light.
Chirped pulse amplification ( CPA) is a technique for amplifying an ultrashort laser pulse up to the petawatt level, with the laser pulse being stretched out temporally and spectrally, then amplified, and then compressed again. [1] The stretching and compression uses devices that ensure that the different color components of the pulse travel ...
In the above formula for r s , if we put = / (Snell's law) and multiply the numerator and denominator by 1 / n 1 sin θ t , we obtain r s = − sin ( θ i − θ t ) sin ( θ i + θ t ) . {\displaystyle r_{\text{s}}=-{\frac {\sin(\theta _{\text{i}}-\theta _{\text{t}})}{\sin(\theta _{\text{i}}+\theta _{\text{t}})}}.}
1 m −1. Illustration of the relationship between optical power in dioptres and focal length in metres. A dioptre ( British spelling) or diopter ( American spelling ), symbol dpt, is a unit of measurement with dimension of reciprocal length, equivalent to one reciprocal metre, 1 dpt = 1 m−1. It is normally used to express the optical power ...
Lorentz factor. where and v is the relative velocity between two inertial frames . For two frames at rest, γ = 1, and increases with relative velocity between the two inertial frames. As the relative velocity approaches the speed of light, γ → ∞. Time dilation (different times t and t' at the same position x in same inertial frame)
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.
Thomas precession gives a correction to the precession of a Foucault pendulum. For a Foucault pendulum located in the city of Nijmegen in the Netherlands the correction is: ω ≈ 9.5 ⋅ 10 − 7 a r c s e c o n d s / d a y . {\displaystyle \omega \approx 9.5\cdot 10^{-7}\,\mathrm {arcseconds} /\mathrm {day} .}
In the physical sciences and electrical engineering, dispersion relations describe the effect of dispersion on the properties of waves in a medium. A dispersion relation relates the wavelength or wavenumber of a wave to its frequency. Given the dispersion relation, one can calculate the frequency-dependent phase velocity and group velocity of ...
It can readily be seen that the formula above for motion along the equator follows from the more general equation below for any latitude where along the equator v = 0.0 and = a r = 2 Ω u cos ϕ + u 2 + v 2 R {\displaystyle a_{r}=2\Omega u\cos \phi +{\frac {u^{2}+v^{2}}{R}}}