01 Optics II Introduction

Optics degree flow chart

“Quit Coughing, Dude! For The Absolute Peace of God.”

Geometric optics fundamentals

Physical optic fundamentals

What does snall’s law represent?

Paraxial optics (first order optics) of a single refracting surface

Snell law formula

What does the small angle approximation of Snell’s law say?

Small-angle approximations apply to Snell’s law: sin𝜃≈𝜃, cos𝜃≈𝜃, tan𝜃≈𝜃 in radians.

What does the thin lens equation represent?

the relationship between object distance, image distance & focal length of a refracting surface or lens

Thin lens equation

In thin lens, when is the image a real image vs. a virtual image?

Real image if it is on the right of the lens. Virtual image if it is in the left of the lens.

What does the thin lens maker’s equation represent?

relationship between the focal length (power) of a refracting surface or lens with its geometry & refractive index

Thin lens maker’s equation

What category of optics do thin lens equations represent?

Paraxial optics (First-order optics)

Index of refraction formula

Ratio of speed of light in air (vacuum) to medium (>1)

What equation represent light refraction?

Snell’s law

What is the index of refraction dependent on?

Speed of light in the medium. Speed of light = (frequency)(wavelength). Therefor, wavelength dependency.

n = n(λ): Chromatic aberration

Average index of refraction of ocular components

1.376

Index of refraction of keratometric

1.3375

Law of reflection

angle of incidence = law of reflection

Reflectance definition & it’s dependencies

The amount of light reflected at an optical surface. It depends on angle of incidence & refractive indices.

Brewster angle definition

Angle of incidence at which no polarized light is reflected

The amount reflected for normal incidence is dependent…

the index difference at each optical surface

What is the formula for determining the reflectance for normal incidence of light?

Fresnel’s formula!

What is S & P polarization?

What is the formula for determining the reflectance unpolarized light?

What is the percent reflectance of the ocular interface between air & tear film? Which purkinje image is does this represent?

2.2941% & Purkinje image I

Transmittance of light through ocular components experiences light loss due to?

reflection, absorption & scatter

Index matching definition

When two optical medias with the same optical index are put together to form an optical interface, the optical interface will have no optical impact.

What is oil-immersion microscopy an application of?

index matching

Tip vs. Tilt of a refracted light rays

• Tip: rotation about the x-axis (pitch)

• Tilt: rotation about the y-axis (yaw)

How to fix of the desired path of light ray entering an irregular shaped cornea?

We can adjust the entering rays local tip & tilt at the surface of the surface of the cornea & direct the light ray to its intended location.

What information is needed in order to perform optical ray tracing?

Surfaces, thickness & refractive indices