D i.e. Blue & yellow 

Macular lesion tends to produce blue-yellow Q defects and optic nerve lesions produce red green defects Q

B i.e. Hereditary Colour Blindness (Achromatopsia)

• An individual with normal colour vision is k/a trichromate. In colour blindness, faculty to appreciate one or more primary colours is either defective (anomalous) or absent (anopia). It may be congenital or acquired.
• Colour blindness is usually a hereditary condition that is present by birth, and though it is more common in males, it can occur in females also. It can also be an acquired condition through diseases of optic nerve or macula but is not normal age-related phenomena. There is no treatment.
• Red & green pigment cones are coded on X-Chromosome and Blue cones on Chromosome 7.

A i.e. More common in males

D. i.e. Tritanomalous

• So anopics have dichromatic colour vision i.e. (are able to see two primary colours) & anomalous have trichromatic colour vision with anomaly (i.e. mechanism to appreciate all 3 primary colours is present but is defective for one or two of them)
• Protan means first, deutan means second, and tritan means third. According to decreasing wavelength it is used for red (550-570 nm, so protan), green (520-540 nm, so deuteran) and blue (410-424 nm, so tritan).

A i.e. Red

C i.e. Protonomaly

A i.e., Mainly congenital B i.e., Can be tested by Farnsworth 100 hue test; C i.e. Ishihara chart test red/ green colour blindness 

Tests for color vision

Pseudoisochromatic charts

–   Ishihara plates mainly to screen congenital protan & deuterans (i.e., red & green defects)Q

–   Hardy -Rand – Rittler plates is more sensitive to Ishihara since it can defect all three congenital defects

• Edridge Green lantern test : the subject has to identify various colours shown to him (in lantern) & judgement depends on mistake he makes.
• City university test : a spectroscopic test where subject is asked to match central colour to its closest hue from 4 peripheral surrounding colour in each of 10 plates.
• Fansworth Munsell 100 hue test is the most sensitiveQ for both congenital & aquired colour defects. It
  consists of 85 hue caps (not 100) and vision is judged by error score i.e., higher score = poorer vision.
• Fansworth D 15 hue discrimination test is similar test but utilizes only 15 hue caps
• Nagel\’s anomaloscope (asked to mix red & green to make a given shade)
• Holmgren\’s wool testQ

Ans. Sex-linked disorder

Ans. Increased sclerosis of the crystalline lens

Ans.B. Deuteranopes

Red-green color blindness is the most common type of color deficiency. Also known as deuteranopia, this is most likely a congenital condition.

For defective (anomalous) colour vision, suffix anomalous is used; and for absent colour suffix anopia is used.