Ocular Anatomy: Unit 1

Christian Huygens

Proposed wave theory of light.

Leon Foucault

Speed of light

Sir Isaac Newton

Developed corpuscular theory of light.

Albert Einstein

Speed of light is constant

Max Planck

photons

James Maxwell

electromagnetic theory

Wave theory of light

Light behaves as a wave.

Speed of light

Constant speed of 299,792 km/s.

Electromagnetic theory

Describes light as electromagnetic waves.

Wavelength

Distance between consecutive wave peaks.

Frequency

Number of wave cycles per second.

Gamma rays

High-energy electromagnetic radiation.

Visible light

Electromagnetic radiation visible to humans.

Snell's law

Describes refraction based on angles.

Angle of incidence

Angle between incoming light and normal.

Convex lens

Converging lens that focuses light. Plus powered

Concave lens

Diverging lens that spreads light. Minus powered

Emmetropia

Normal vision without refractive error.

Myopia

Nearsightedness; image in front of retina.

Hyperopia

Farsightedness; image behind the retina.

Astigmatism

Condition with multiple focal points.

Presbyopia

Loss of accommodation with age.

Focal length of a lens

Distance from lens to focus point.

Power of a lens

Measured in diopters; P = 1/f.

Transposition

Changing lens prescription format.

Spherical equivalent

Simplified lens prescription combining powers.