Eye Disease and Their View. – Color-Blind – Macular degeneration – Cataracts – Diabetic...
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Transcript of Eye Disease and Their View. – Color-Blind – Macular degeneration – Cataracts – Diabetic...
Eye Disease and Their View
– Color-Blind– Macular degeneration– Cataracts– Diabetic retinopathy– Glaucoma – Presbyopia-refractive error– Diplopia– Floaters– Night Blindness
Common Eye Diseases
Internal anatomy of the eye
Color blindnessDeuteranomaly: malfunctioning green cone (common)Deuteranopia: missing green cone (rare)Protanomaly: malfunctioning red cone (rare)Protanopia: missing red cone (rare)
Types of Color Blindness
Visual comparison
The Retina
Retinal blood vessels
Macula
(fovea in centre)
Optic nerve
What is Macular Degeneration?
• Wet and ray macular degeneration causes blurred vision
• Macula-is the fovea centralis-focal point of vision.– Wet macular degeneration -blood vessels build up
under retina and leak blood– Dry macular degeneration -tissue in the macula
becomes thin and breaks down.• Difficulty distinguishing visual images
Macular Degeneration (MD)
What is a cataract?
• A cataract is the clouding of the lens inside the eye. With a cataract, light is scattered as it enters the eye, causing blurred vision.
Cataract
What is diabetic retinopathy?
• This condition is a complication of diabetes• It affects the small blood vessels of the retina• Blood vessels begin to leak and bleed inside
the eye
Diabetic retinopathy
What is glaucoma?
• It is a disease that affects the optic nerve at the back of the eye
• Relieving pressure on the nerve reduces progression of the disease
• Early detection and treatment can slow the vision loss
• Caused by build up of aqueous humor faster than it is degraded. Pressure increases in eye.
Glaucoma
What is presbyopia(refractive error)?
• Refractive error is a focusing disorder of the eye
• Over the age of 40 years, 22 per cent of the population has refractive error
• It is correctable by wearing glasses or contact lenses or refractive laser surgery (selected cases)
• Inability to accommodate, near point of vision moves further away.
Presbyopia
What is diplopia?
• Deviating eye causes double vision.• Turning eye may eventually become blind as a
result of the brain suppressing the image from the wandering eye.
Diplopia
What are floaters?
• Spots or specs that appear to be “floating” across your field of view.
• Most eye floaters are caused by age-related changes that occur as the jelly-like substance (vitreous) inside your eyes becomes more liquid.
• Microscopic fibers within the vitreous clump together and cast tiny shadows on the retina
Floaters
What is night blindness?
• Night blindness (also called nyctalopia) is the inability to see well at night or in poor light. It is not a disease, but rather a symptom of an underlying disorder or problem, especially untreated nearsightedness.
• Can be caused by lack of vitamin A which effects the rods.
Night Blindness