Colour Vision

These flashcards cover key concepts from the lecture on colour vision, including types of colour vision abnormalities, testing methods, and the biology of colour perception.

What are the two main types of congenital abnormalities of colour vision?

Dichromacies and Anomalous Trichromacies.

What does acquired abnormality of colour vision often relate to?

Aging and eye conditions, as well as colour vision changes post brain injury.

What is the significance of the visible light spectrum in human colour perception?

It indicates the wavelengths that are perceived as different colours by the human eye, typically from about 400 nm to 700 nm.

How many photopigments are present in the human eye under photopic conditions?

Three photopigments, allowing for trichromatic vision.

What kind of deficiencies are associated with missing types of cones?

Dichromatic Colour Deficiency, including Protanopia, Deuteranopia, and Tritanopia.

What condition is characterized by a loss of colour vision due to brain damage?

Cerebral Achromatopsia or dischromatopsia.

What colour vision test uses pseudoisochromatic plates?

Ishihara Test.

What is the purpose of an Anomaloscope?

To diagnose and assess colour vision deficiencies.

Describe the mechanism of Anomalous Trichromacy.

It occurs when all three cone types are present but one has an abnormal absorption curve.

What are the two opponent colour channels in the human visual system?

Red/green and yellow/blue.

What is a normal response of the human eye to wavelength stimuli?

Any wavelength will produce three responses, which are less likely to be confused with other single wavelengths.

What is the prevalence rate of Protanopia in males?

Approximately 1%.

What distinguishes Rod or Cone Monochromacy?

There is only one type of photoreceptor present, leading to no colour perception.

What are the consequences of the absence of the M-type pigment?

It results in Deuteranopia and affects the ability to discriminate certain colours.

What does the Farnsworth-Munsell 100 HUE test evaluate?

It assesses an individual's colour discrimination abilities.

What information does the term 'trichromacy' refer to?

It indicates the presence of three distinct colour processes in human vision.