Eyes (to be) _____ organs that detect light. In the human eye, light (to enter) __________ the pupil.Light (to focus) __________on the retina by the lens. Light-sensitive nerve cells called rods (for brightness) and cones (for color) (to react) _________ to the light. They (to interact) _________ with each other and (to send) ___________ messages to the brain that indicate brightness, color, and contour.
The first proto-eyes evolved among animals 540 million years ago. Almost all animals have eyes, or descend from animals that did.
Anatomy of the mammalian eye
The most important parts of the eye (to be) _____ :
1. pupil
2. anterior chamber
3. cornea
4. iris
5. lens cortex
6. lens nucleus
7. conjuntiva
8. optic disc
9. central retinal artery
10. central retinal vein
11. optical nerve
12. macula
13. sclera
14. retina
BLINDNESSWhat (to be) _____ blindness?
Some people (to bear) _______________ with a visual impairment. A person who (to be) ______ blind (to have) _________ a high degree of vision loss. Only about 18 per cent of blind people (to be) _____ totally blind - most can(to distinguish) ______________ between light and dark.
When someone (to be) _____ partially sighted, they (to have) ____________ a less severe loss of vision. Partially sighted people can (to see) _____________ more than blind people but less than sighted people.
Blindness can (to cause) _____________ difficulty with performing everyday tasks
Blindness can (to cause) _______________ difficulty with performing everyday tasks such as cooking, dressing, reading and writing. When outside shopping or going for a walk, blindness can (to create) __________________ problems.
The risk of physical and social isolation (to be) ______ greater for those who (to be) ______ blind or partially-sighted as it can (to be) ______harder for them to get out and make new friends than it (to be) _____for people who (to be) _____ fully sighted. Blindness can also (to be) ______ an expensive condition because of, for example, the costs of special equipment.
What _______the causes (to be)?
Accidents and disease (to be) _______ often responsible for blindness while some people (to bear) ________________ blind or partially sighted. Common causes (to include) __________ age-related macular degeneration, cataracts, retinal detachment, diabetic retinopathy and glaucoma.
Having an eye test at least every two years can (to help) ____________ to detect problems that may (to need) _______________ treatment.
It (to be) _____ important to wear protective eyewear in situations where accidental eye damage may (to occur) _________________, for example, at work, when playing sport. Some conditions, such as glaucoma and cataracts, can (to treat) ________________to help preserve vision.
Daily life
The use of a guide dog or asking a sighted friend to help (to overcome) ________________ problems for blind or partially sighted people outside.
Helpful techniques (to include) _____________ using colour-coded buttons to help with dressing, and counting as water (to pour) ___________ into a teapot to identify when it's full.
Braille or Moon (to help) _________ with reading and writing. Many people (to prefer) ____________ to listen to audio cassettes and CD's. The telephone and computers (to help) ___________ many to communicate.
GLAUCOMATypes
There (to be) ______ two common types of glaucoma: acute and chronic. Acute glaucoma - mild attacks (to cause) _____________ pain in the eyes and haloes around lights. These symptoms (to relieve) ______________ by sleeping. Full-blown attacks (to cause) __________ rapid deterioration of vision, intense eye pain, redness and watering of the eye, sensitivity to bright light, haloes around lights, nausea and vomiting. Acute glaucoma (to be) _________ more common in women than in men.
Chronic glaucoma - often (to cause) _____________ no symptoms until permanent damage (occur) _____ already __________. Symptoms may then (to include) ___________ loss of peripheral vision and, eventually, blurring of objects directly in front of the person.
There (to be) _____ also two rarer types of glaucoma: congenital glaucoma and glaucoma that (to be) _____ secondary to conditions such as uveitis or a side effect of medication.
Glaucoma mainly (to affect) ___________ people over the age of 60 and (to be) _____ more common with increasing age.
Treatment
Untreated glaucoma can (to lead) ___________ to blindness. Eye drops or tablets may be prescribed to reduce fluid production and consequently reduce pressure in the eye.
Laser or surgical treatment may (to use)___________ when medical treatment isn't sufficiently effective.
Screening
People over the age of 40 (to advise) ___________ to have their eyes tested every two years to check for signs of glaucoma. If glaucoma (to identify) _____________early enough, treatment can (to give) ____________ to prevent further damage and reduce the risk of blindness.
These tests (to be) _____ available at your local optician and should(to include) ___________:
• examination of the optic disc
• measurement of the pressure in the eye
• checking of peripheral vision (by looking for a sequence of spots of light on a screen).
CATARACTWhat _____ cataracts (to be) ______________?
A cataract (to be) ______ a clouding of the lens in the eye
A cataract (to be) _____a clouding of the lens in the eye. This (to prevent) ____________ light from passing through the lens and reaching the back of the eye, interfering with vision.
Cataracts most commonly (to develop) _________ as people (to get) ______ older. These (to call) _____________ age-related cataracts. Congenital cataracts (to be) _______ present from birth and (to be) _______ usually the result of exposure to infection, radiation or drugs before birth, or because of a genetic problem.
Other causes of cataracts (to include) _______________ illnesses such as diabetes, certain drug treatments, long-standing inflammation and injury.
Symptoms
Age-related cataracts (to develop) _____________ gradually
The symptoms of age-related cataracts (to develop) ________________ gradually, getting worse over many years. Blurred and cloudy vision (to be) ____ common. It may (to be) _____ difficult to see in dim light and bright lights may appear more glaring. Colours may (to appear) ___________ different to how they once did and there may (to be) _______ a yellow tinge to vision.
Left untreated, congenital cataracts can (to result) _____________ in permanent visual loss.
Who (to affect) _______________?
The older someone (to be) ______, the more likely they (to be) ______ to suffer from age-related cataracts. It (to estimate) __________________ that around 71 per cent of people over the age of 85 (to have) _______________ a cataract bad enough to affect their sight. Women (to affect) _____ more commonly ___________________ than men.
Prevention and treatment
Good management of conditions such as diabetes (to reduce) ________the risk of cataracts developing.
It (not to be) ___________ possible to prevent age-related cataracts, but regular eye tests can (to help) ______________ to detect problems early.
The most effective treatment (to be) ______to remove the affected lens surgically and (to replace) __________________ it with a new one.
