INCLUSIVE COLOUR (CONT) . SIGHT
Cataracts gradually cause the lens (which is normally transparent) to become opaque. This can hinder sight quality. Sensitivity to bright light can increase and things may appear more yellow than before. Glaucoma is the name given to a group of eye conditions when optic nerve damage affects your vision. Glaucoma is also referred to as tunnel vision. Effects can be gradual, and you may lose up to 40% of your peripheral vision before anything is noticed. This nerve carries information about what is being seen from the eye to the brain and as it becomes damaged vision is lost. High eye pressure (not related to high blood pressure) is a common cause of glaucoma. Symptoms include missing patchy vision and even serious vision loss.
Diabetic Eye Disease is a group of eye conditions that affect people with diabetes. The longer a person has diabetes the higher the risk for developing an eye condition, but not everyone who has diabetes will develop an eye condition. Regular specific eye checks can detect early symptoms and can reduce the risk by 95% (National Eye Institute). The Ageing Eye is when the eye subtly changes as we get older, it is a natural process of ageing. As we get older, themuscles that control the pupil lose some of their strength; this results in the pupil becoming smaller and less responsive to changes in light conditions. An older person requires more light than a younger person to be able to see comfortably. An ageing eye is more sensitive to glare or dramatic changes
Colour Vision deficiency is usually genetic and inherited. It can also be a result of diabetes, multiple sclerosis and other long termconditions, exposure to certain chemicals, or a side effect of somemedicines. An inherited condition will stay the same throughout a person’s life. Colour Vision Deficiency is sometimes referred to as colour blindness but the ability not to see any colour is very rare. The eye has three types of cone cells and each are sensitive to different light wavelengths; red, green and blue. These work in daylight conditions and help the eye to process light and send signals to the brain which interprets the information into colour. The cone cells work together to enable a full spectrumof colours to be seen. A computer also uses red, green and blue light to create all the colours seen on a computer screen. Colour Vision Deficiency happens when some or all of the cone cells are missing or don’t work properly.
fromdark spaces to light due to the slower reaction time of the pupil. Cone cells in the retina are responsible for colour vision and as the eye gets older these decline. Colours can appear faded and not as vibrant, blues in particular, appear grey and less prominent. Brighter blues and richer warm tones are best suited for colour schemes for older people. Contrast is not as noticeable and in turn this can affect the ability to perceive depth and increase the risk of falls. A loss in peripheral vision is also common in an aged eye, and 20% of peripheral vision can be lost.
Other symptoms can result in colours appearing duller, difficulty distinguishing between red and black and sometimes although not common, difficulty distinguishing between blue and yellow. There are varying levels of colour vision deficiency. Normal vision - Trichromacy (All three cones are responsive to light wavelengths). Anomalous Trichromacy - All three cones are responsive to light but there is misalignment which can cause colour vision deficiency, in varying degrees. Dichromacy is when two types of cones are working properly. Protanopia is not being able to perceive red light, deuteranopia is not being able to perceive green light and tritanopia is not being able to perceive blue light. Monochromacy is very rare and effects only 1 in 33,000 people. No colour is seen; only shades of black, white and grey.
Distinguishing between red and green is the most common symptomof Colour Vision Deficiency, this affects 1 in 12 men and 1 in 200 women. (NHS 2020)
Age-related macular degeneration
Normal vision
Glacoma
Ageing eye
As we get older the muscles that control the pupil lose some of their strength, this results in the pupil becoming smaller and less responsive to changes in light conditions.
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