A visual study guide with worked problems for opticians and optometry students. It follows light from the source, through glass, to the eye.
The visible range used throughout Topic 1: 380 to 760 nm, or 0.38 to 0.76 µm.
The handbook is for beginners in optics, working opticians, and anyone who wants to understand how light reaches the eye through lenses. Each topic uses clear explanations, clean diagrams and numerical examples. It was written by a qualified optician from their own lecture notes, and each topic was checked against standard textbooks and professional sources.
What light is: theories of its nature, wavelength and frequency, interference, diffraction, polarization and dispersion.
How a ray behaves: basic concepts and laws, reflection and refraction, total internal reflection, mirrors, plates and prisms.
Prisms, spherical surfaces, magnification, spherical mirrors, lenses and sphero-cylinders: the basis of spectacle and contact lenses.
The clinic workflow, and recalculating lens power from spectacles to contact lenses.
Filter by part. Page numbers refer to the handbook, and the highlighted line is the key relation from Appendix A.
Once you know the layout of one topic you know them all. Each ends with solved problems, self-check questions with answers, and a glossary.
The aims of the topic, listed at the start.
The most important points that should stay in memory.
Where students most often go wrong, including the two sign-convention boxes.
How the topic connects to work in optics and the eye-care office.
Deeper explanations and history. Skip them on a first read.
The topic's main formulas, repeated in Appendix A.
The handbook does not replace your official textbook or your instructor's guidance. Where they differ, follow your course. The practice modules are for education. Contact lenses should only be fitted by a qualified eye care professional.
Each one runs a formula from the book with the same constants and sign rules. Change a value and the result updates.
c = λ·ν, T = 1/ν, E = h·ν with c = 3·10⁸ m/s and h = 6.63·10⁻³⁴ J·s. The default is the green light from the handbook's solved problem.
n₁·sin θ₁ = n₂·sin θ₂. Total internal reflection needs n₁ > n₂ and θ₁ above the critical angle sin θc = n₂/n₁. Defaults: a ray in glass meeting air.
FCL = Fsp / (1 − d·Fsp), with d in metres. The reverse is Fsp = FCL / (1 + d·FCL). Most useful above about ±4–5 D. The result is a starting point, since the final lens is chosen at the fitting.
S′ = S + C, C′ = −C, axis turned by 90°. The handbook's example: OD −4.00 −1.00 × 180 becomes −5.00 +1.00 × 90.
A sample from the handbook's formula appendix. The full list covers every topic and both practice modules.
| Formula | Meaning | Topic |
|---|
The calculators and summaries on this site are a sample. The guide gives you every explanation, diagram and worked problem in order.
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