Test your basic knowledge of Optics1. What is the mean angle of resolution of an eye with a 6/6 acuity?
2. How far away can an eye with 6/6 visual acuity read the 6/24 lines?
3. What is the Snell's law of reflection?
4. What is the apex angle in degrees of a 10 dioptres prism?
5. The nodal point of a lens is at the intersection between the _____________ and the ___________________.
6. The refracting power of a cylindrical lens is at __________ degrees to the axis.
7. The image produced by a negative lens is ____________, ___________ and _____________.
8. A focimeter measures the _________________ of a lens
9. A decentration of 10 mm from the optical centre of a +5 dioptre lens produces a prismatic effect of _______ prism dioptres
10. A X8 loupe has an equivalent power of _______ dioptres.
11. Two lens of power +4 dipotres are separated by a distance of 10 cm. The final vergence of a ray of light initially parallel to the principle axis is _______ dioptres
12. A lens of +10 dipotres fully correct an hyperopia and now the lens is moved forward 10mm, what is the new lens power needed to correct the hyperopia?
13. In trifocals the intermediate lens usually has an addition of _______ dioptre over the distance correction.
14. The LTF stands for _________________ when considering tints.
15. Relative spectacle magnification =
16. Which combination make up 0.50 Jackson cross cylinder?
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