Biomaterial Database

Visual acuity in the blue cone monochromat. 1972

D G Green

1. To isolate the blue cones of the normal eye, blue sine-wave gratings were superimposed on a bright yellow background. Threshold contrasts for resolution of the gratings were then determined.2. Under these conditions visual acuity for high contrast gratings on four normal subjects was on the average 0.31 min(-1). This is about a factor of 6 lower than grating acuity under optimal conditions.3. The contrast sensitivity of two subjects who lack the normal red and green receptor mechanisms was measured using blue sinusoidally modulated gratings. Visual acuity was found to be greatly reduced from normal. The low acuity of these individuals is due to both a reduction in contrast sensitivity and a reduction in resolution.4. The spatial resolving characteristics of these subjects resembles the vision of the normal eye under conditions which isolate the blue sensitive mechanisms.5. The vision of the cone monochromat differs significantly from that of the more typical rod monochromat. The rod monochromat has even lower acuity than the blue cone monochromat for high contrast gratings but has much greater contrast sensitivity for gratings of low spatial frequency.

UI	MeSH Term	Description	Entries
D010786	Photoreceptor Cells	Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.	Ciliary Photoreceptor Cells,Ciliary Photoreceptors,Rhabdomeric Photoreceptor Cells,Rhabdomeric Photoreceptors,Cell, Ciliary Photoreceptor,Cell, Photoreceptor,Cell, Rhabdomeric Photoreceptor,Cells, Ciliary Photoreceptor,Cells, Photoreceptor,Cells, Rhabdomeric Photoreceptor,Ciliary Photoreceptor,Ciliary Photoreceptor Cell,Photoreceptor Cell,Photoreceptor Cell, Ciliary,Photoreceptor Cell, Rhabdomeric,Photoreceptor Cells, Ciliary,Photoreceptor Cells, Rhabdomeric,Photoreceptor, Ciliary,Photoreceptor, Rhabdomeric,Photoreceptors, Ciliary,Photoreceptors, Rhabdomeric,Rhabdomeric Photoreceptor,Rhabdomeric Photoreceptor Cell
D003117	Color Vision Defects	Defects of color vision are mainly hereditary traits but can be secondary to acquired or developmental abnormalities in the CONES (RETINA). Severity of hereditary defects of color vision depends on the degree of mutation of the ROD OPSINS genes (on X CHROMOSOME and CHROMOSOME 3) that code the photopigments for red, green and blue.	Achromatopsia,Color Blindness,Monochromatopsia,Color Blindness, Acquired,Color Blindness, Blue,Color Blindness, Green,Color Blindness, Inherited,Color Blindness, Red,Color Blindness, Red-Green,Color Vision Deficiency,Deutan Defect,Protan Defect,Tritan Defect,Achromatopsias,Acquired Color Blindness,Blindness, Color,Blue Color Blindness,Color Blindness, Red Green,Color Vision Defect,Color Vision Deficiencies,Defect, Color Vision,Defect, Deutan,Defects, Color Vision,Deficiencies, Color Vision,Deficiency, Color Vision,Green Color Blindness,Inherited Color Blindness,Red Color Blindness,Red-Green Color Blindness,Vision Defect, Color,Vision Defects, Color,Vision Deficiencies, Color,Vision Deficiency, Color
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013028	Space Perception	The awareness of the spatial properties of objects; includes physical space.	Perception, Space,Perceptions, Space,Space Perceptions
D014792	Visual Acuity	Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.	Acuities, Visual,Acuity, Visual,Visual Acuities