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