What is a cataract?
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.

A cataract can occur in either or both eyes. It cannot spread from one eye to the other.



What is the lens?
The lens is a clear part of the eye that helps to focus light, or an image, on the retina. The retina is the light-sensitive tissue at the back of the eye.

In a normal eye, light passes through the transparent lens to the retina. Once it reaches the retina, light is changed into nerve signals that are sent to the brain.

The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.



What causes cataracts?
The lens lies behind the iris and the pupil. It works much like a camera lens. It focuses light onto the retina at the back of the eye, where an image is recorded. The lens also adjusts the eye's focus, letting us see things clearly both up close and far away. The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.

But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see.

Researchers suspect that there are several causes of cataract, such as smoking and diabetes. Or, it may be that the protein in the lens just changes from the wear and tear it takes over the years.

How do cataracts affect vision?
Age-related cataracts can affect your vision in two ways:

Clumps of protein reduce the sharpness of the image reaching the retina. The lens consists mostly of water and protein. When the protein clumps up, it clouds the lens and reduces the light that reaches the retina. The clouding may become severe enough to cause blurred vision. Most age-related cataracts develop from protein clumpings. When a cataract is small, the cloudiness affects only a small part of the lens. You may not notice any changes in your vision. Cataracts tend to “grow” slowly, so vision gets worse gradually. Over time, the cloudy area in the lens may get larger, and the cataract may increase in size. Seeing may become more difficult. Your vision may get duller or blurrier.

The clear lens slowly changes to a yellowish/brownish color, adding a brownish tint to vision. As the clear lens slowly colors with age, your vision gradually may acquire a brownish shade. At first, the amount of tinting may be small and may not cause a vision problem. Over time, increased tinting may make it more difficult to read and perform other routine activities. This gradual change in the amount of tinting does not affect the sharpness of the image transmitted to the retina. If you have advanced lens discoloration, you may not be able to identify blues and purples. You may be wearing what you believe to be a pair of black socks, only to find out from friends that you are wearing purple socks.

When are you most likely to have a cataract?
The term “age-related” is a little misleading. You don't have to be a senior citizen to get this type of cataract. In fact, people can have an age-related cataract in their 40s and 50s. But during middle age, most cataracts are small and do not affect vision. It is after age 60 that most cataracts cause problems with a person's vision.

Who is at risk for cataract?
The risk of cataract increases as you get older. Other risk factors for cataract include:

Certain diseases (for example, diabetes).
Personal behavior (smoking, alcohol use).
The environment (prolonged exposure to ultraviolet sunlight).
What are the symptoms of a cataract?
The most common symptoms of a cataract are:

Cloudy or blurry vision.
Colors seem faded.
Glare. Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.
Poor night vision.
Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)
Frequent prescription changes in your eyeglasses or contact lenses.
These symptoms also can be a sign of other eye problems. If you have any of these symptoms, check with your eye care professional.

Are there different types of cataract?
Yes. Although most cataracts are related to aging, there are other types of cataract:

Secondary cataract. Cataracts can form after surgery for other eye problems, such as glaucoma. Cataracts also can develop in people who have other health problems, such as diabetes. Cataracts are sometimes linked to steroid use.
Traumatic cataract. Cataracts can develop after an eye injury, sometimes years later.
Congenital cataract. Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.
Radiation cataract. Cataracts can develop after exposure to some types of radiation.
How is a cataract detected?
Cataract is detected through a comprehensive eye exam that includes:

Visual acuity test. This eye chart test measures how well you see at various distances.
Dilated eye exam. Drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
Tonometry. An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
Your eye care professional also may do other tests to learn more about the structure and health of your eye.

Blindness and vision loss
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Blindness is a lack of vision. It may also refer to a loss of vision that cannot be corrected with glasses or contact lenses.

Partial blindness means you have very limited vision.
Complete blindness means you cannot see anything and DO NOT see light. (Most people who use the term "blindness" mean complete blindness.)
People with vision that is worse than 20/200 with glasses or contact lenses are considered legally blind in most states in the United States.

Vision loss refers to the partial or complete loss of vision. This vision loss may happen suddenly or over a period of time.

Some types of vision loss never lead to complete blindness.

Causes
Vision loss has many causes. In the United States, the leading causes are:

Accidents or injuries to the surface of the eye (chemical burns or sports injuries)
Diabetes
Glaucoma
Macular degeneration
The type of partial vision loss may differ, depending on the cause:

With cataracts, vision may be cloudy or fuzzy, and bright light may cause glare
With diabetes, vision may be blurred, there may be shadows or missing areas of vision, and difficulty seeing at night
With glaucoma, there may be tunnel vision and missing areas of vision
With macular degeneration, the side vision is normal, but the central vision is slowly lost
Other causes of vision loss include:

Blocked blood vessels
Complications of premature birth (retrolental fibroplasia)
Complications of eye surgery
Lazy eye
Optic neuritis
Stroke
Retinitis pigmentosa
Tumors, such as retinoblastoma and optic glioma
Total blindness (no light perception) is often due to:

Severe trauma or injury
Complete retinal detachment
End-stage glaucoma
End stage diabetic retinopathy
Severe internal eye infection (endophthalmitis)
Vascular occlusion (stroke in the eye)
Blindness and vision loss
Email this page to a friend Print Facebook Twitter
Blindness is a lack of vision. It may also refer to a loss of vision that cannot be corrected with glasses or contact lenses.

Partial blindness means you have very limited vision.
Complete blindness means you cannot see anything and DO NOT see light. (Most people who use the term "blindness" mean complete blindness.)
People with vision that is worse than 20/200 with glasses or contact lenses are considered legally blind in most states in the United States.

Vision loss refers to the partial or complete loss of vision. This vision loss may happen suddenly or over a period of time.

Some types of vision loss never lead to complete blindness.

Causes
Vision loss has many causes. In the United States, the leading causes are:

Accidents or injuries to the surface of the eye (chemical burns or sports injuries)
Diabetes
Glaucoma
Macular degeneration
The type of partial vision loss may differ, depending on the cause:

With cataracts, vision may be cloudy or fuzzy, and bright light may cause glare
With diabetes, vision may be blurred, there may be shadows or missing areas of vision, and difficulty seeing at night
With glaucoma, there may be tunnel vision and missing areas of vision
With macular degeneration, the side vision is normal, but the central vision is slowly lost
Other causes of vision loss include:

Blocked blood vessels
Complications of premature birth (retrolental fibroplasia)
Complications of eye surgery
Lazy eye
Optic neuritis
Stroke
Retinitis pigmentosa
Tumors, such as retinoblastoma and optic glioma
Total blindness (no light perception) is often due to:

Severe trauma or injury
Complete retinal detachment
End-stage glaucoma
End stage diabetic retinopathy
Severe internal eye infection (endophthalmitis)
Vascular occlusion (stroke in the eye)

India is bestowed with exotic fruits; one of them being custard apple, also known as sitaphal or sharifa in Hindi. Custard apple has a unique taste, essential nutrients and various impressive health benefits. It is a tropical fruit native to Central America and scientifically known as Annona reticulata. Closely related to bullock's heart, or ramphal, this fruit is vaguely heart shaped and is generally green in colour. Custard apple is soft and contains a few black inedible seeds. It is believed that the name 'custard' is given considering the consistency of the fruit. It is a blend of sweet and tangy flavour, almost similar to a citrus fruit.Custard apple is said to possess nutrients that include vitamin-C and vitamin-B6 along with minerals like calcium, magnesium and iron. The fruit contains no fats or cholesterol, but may have some calories to add up. In addition, custard apple has various polyphenolic compounds with antioxidant properties that boost the nutritive value of the exotic fruit.

Here are some of the health benefits of custard apple that will convince you to add this fruit in your daily diet.

1. May Help Improve Vision

Custard apple is said to be an excellent source of riboflavin and vitamin-C that helps combat age-related macular degeneration and other eye-related problems.

2. Also Helps Build Immunity

Thanks to the presence of natural antioxidant vitamin-C that makes custard apple an excellent source of boosting the immune system. This vitamin is known for its anti-inflammatory properties. It is said that just a serving this creamy fruit in your daily diet can build better resistant against infections.

3. May Help Reduce Joint Pain

The high amount of magnesium regulates and equalises water balance in the body, and removes acids from the joint, further reducing the risk of developing arthritis. Regular consumption of custard apple may help to fight muscle weakness too.

4. May Help Treat Digestive Issues

The sweet-sour fruit is effective for treating digestive issues by flushing out toxins from the intestine, further aiding in proper functioning of the bowel. In fact, it is said to treat diarrhoea by consuming it in its unripen form, which is dried and crushed.

5. Boosts Haemoglobin Count

The sufficient levels of iron content present in custard apple are beneficial for curing anaemia by increasing blood count. So, load up on custard apple more often.

6. A Skin Friendly Fruit

This fruit acts as a skin rejuvenator; thanks to the essential nutrients it contains. Regular consumption of custard apple is said to thicken and stimulate the collagen that reduces fine lines and wrinkles. It is also known to improve hydration in-and-around the cells, helping the skin glow naturally.

7. Keeps Your Hair Woes At Bay

The vitamin-C content and antioxidant present in custard apple help to regulate sebum production in the scalp, thereby, reducing flaky skin and dandruff. It also inhibits scalp inflammation, preventing hair fall.

Do not miss eating this exotic fruit and bring it to your rescue by adding it in your daily diet.

Your eyes play a significant role in your health. Many steps can be taken to ensure that your eyes are protected and remain as healthy as possible.

Here are some ways to protect your eyes from damage and disease and maintain healthy sight.

- Rest your eyes regularly: If you work all day at a computer screen, you may forget to blink often and end up with fatigued eyes by the end of the day. For every 20 mins that you spend staring at a screen, look at something else that is around 20 ft in front of you for 20 seconds to reduce eye strain.

- Eat vision-healthy foods: Consuming a diet rich in fruits and vegetables promotes eye health. Dark leafy greens, including collard greens, kale, and spinach—contain lutein and zeaxanthin, which are antioxidants that help to prevent the formation of #cataracts. Grapes, too, may also support healthy eyes. Consuming fish rich in omega-3 fatty acids can also prove beneficial.

- Keep your weight under control: Being overweight or obese puts you at a higher risk of developing conditions such as diabetes or other systemic disorders, which may eventually lead to #VisionLoss. Considerable weight loss could potentially reverse eye damage caused by #Diabetes, #HighBloodPressure, and #Obesity.

- Go for regular eye exams: The best thing you can do to look after your sight is to go for regular #EyeTests. Not only does an eye test determine whether or not you need glasses, but it can also spot eye conditions that can be treated effectively if detected early enough.

- Wear sunglasses when outside: In addition to being a trendy fashion accessory, the most important role of sunglasses is to protect your eyes from the ultraviolet (#UV) rays emitted by the sun. When selecting sunglasses, never opt for style over safety. Look for shades that block 99–100 % of #UVA and #UVB radiation and always buy from a reputable source.

रातांधळेपणा :

या आजारात माशाच्या खवल्यासारखे डाग डोळयाच्या पांढ-या भागावर दिसू लागतात. हे डाग बुबुळाच्या बाहेरच्या बाजूला असतात. पण नाकाच्या बाजूला कधी येत नाहीत. डोळयात काजळ घातल्यावर या खरखरीत भागावर काजळ साचून हा भाग उठून दिसतो. या खवल्यासारख्या भागाला बिटॉटचे ठिपके म्हणतात. (बिटॉट हे एका शास्त्रज्ञाचे नाव आहे.) आता हा आजार फार क्वचित आढळतो.

उपचार
'अ' जीवनसत्त्वाचे जास्त शक्तीचे तेलकट औषध बाटलीतून मिळते. याचा एक चमचा म्हणजे दोन लाख युनिट असतात. आजाराच्या उपचारासाठी एकूण सहा लाख युनिट द्यावे लागतात (रोज एक चमचा तीन दिवस).मात्र आजार नसल्यास केवळ एक चमचा द्यावे.

रातांधळेपणा टाळण्यासाठी, सर्व मुलांना 5 वर्षापर्यंत दर 6 महिन्यांनी एक चमचा "अ" जीवनसत्त्वाचा डोस द्यावा.

'अ' जीवनसत्त्वाअभावी येणारे अंधत्त्व हे पूर्णपणे टाळण्यासारखे आहे. त्यासाठी करायची उपाययोजना ही अतिशय साधी आहे. त्यामुळे मुलाचे आयुष्यभराचे भावी नुकसान टाळता येईल.

उपचार केल्यानंतर रातांधळेपणा, डोळयाचा कोरडेपणा, पूर्ण बरा होतो. पण बिटॉटचे ठिपके एकदा तयार झाले की जात नाहीत. मात्र, बुबुळाचा कोरडेपणा व धूसरपणा जाऊन ते परत पूर्ववत चकचकीत होऊ शकते. पण बुबुळ मऊ पडून फुटले तर परत कधीही दृष्टी येऊ शकत नाही. गरोदर मातेस 'अ' जीवनसत्त्वाच्या अभावामुळे रातांधळेपणा येऊ शकतो. म्हणून गरोदर मातेलाही रातांधळेपणासाठी डोस देणे आवश्यक आहे. बुबुळाचा कोरडेपणा व धूसरपणा ही अंधत्त्वाची पूर्वसूचना समजा. यावर अजिबात वेळ न दवडता उपचार करा. या बरोबरीने जंतासाठी बेंडेझोल हे औषध द्यावे.

'अ' जीवनसत्त्वाची कमतरता टाळण्यासाठी हिरव्या पालेभाज्या, (विशेषत: शेवग्याचा हिरवा पाला, पालक, मेथी, इत्यादी) रंगीत फळे (उदा. गाजरे, टोमॅटो,पपई, आंबा,भोपळा, इ.) व प्राण्यांचे मांस, यकृत, अंडी, मासे उपयोगी आहेत. या सर्व पदार्थांमध्ये'अ' जीवनसत्त्व भरपूर असते.

'ड' जीवनसत्त्वाचा अभाव (मुडदूस)
हाडांमध्ये चुन्याचे क्षार जमून हाडे मजबूत होण्यासाठी 'ड' जीवनसत्त्वाची गरज असते. 'ड'जीवनसत्त्वाची कमतरता असल्यास हाडांमध्ये चुन्याचे क्षार न जमल्याने हाडे दुबळी व मऊ बनतात.

लक्षणे व रोगनिदान
- अशा मुलांचे कपाळ पुढे आलेले दिसते.
- घाम जास्त येतो.
- पुढची टाळू वर्षानंतरही वयाच्या प्रमाणात भरलेली नसते.
- एरवी एक वर्ष वयाला खूपच थोडी टाळू शिल्लक राहिलेली असते व दीड वर्षापर्यंत भरून येते.
- विकासाचे टप्पे लांबतात. उदा. आठ-नऊ महिन्यांचे झाले तरी अजून बाळ बसत नाही, एक वर्षाचे मूल उभे राहत नाही, चालण्याचे वय लांबते.
- सांध्याच्या बाजूची हाडांची टोके फुगतात व सांधे सुजल्यासारखे दिसतात. (विशेषत: मनगटे, गुडघे)
- छातीच्या फासळया व पायांना बाक येतो.
- पोट मोठे दिसते.

प्रतिबंधक उपाय
दूध, माशाचे तेल, अंडी, मांस, इत्यादींमध्ये 'ड' जीवनसत्त्व भरपूर असते. सूर्यप्रकाशात (विशेषत: कोवळे ऊन) त्त्वचेखाली 'ड' जीवनसत्त्व त्यार होत असते. म्हणून मुले बाहेर हिंडायच्या वयाची झाली, की मुडदूस आपोआप कमी होतो. बाळास रोज सकाळच्या कोवळया उन्हात 15 मिनिटे ठेवल्यास 'ड' जीवनसत्त्वाची गरज भागते.