Posts Tagged ‘damage’
With the wide selection of lutein products, some people become skeptical about the effectiveness of these products in various forms. Some sellers make promising claims about their lutein products, but people with poor vision may wonder whether lutein will actually improve vision.
In fact, lutein products can only help patients with bad vision, which is exactly caused by a lutein deficiency. Lutein in the eyes can protect eye tissue from the damage caused by free radicals, which are highly reactive atoms. These free radicals in the eye act on other healthy atoms and damage them, because they require a supply of free electrons. Lutein can effectively fight against these radicals.
In either dry or wet form, age-related macular degeneration is the most common result of these reactive radicals, especially in elderly individuals. And lutein has been found to reverse macular degeneration by combating these radicals and thus improve overall eyesight.
Accounting for 80% of vision defects, dry form of AMD is usually caused by abnormal growth of blood vessels below the retina, which in turn results from reactive chemicals in the tissue. Fortunately, lutein supplements have proven to reverse this condition a lot.
In fact, lutein acts like a neutralizing agent and prevents harmful light rays from damaging the tissue in the macula, which is situated in the center of the retina. As a result, a deficiency of lutein can lead to eye tissue damage.
Lutein is actually only one of the 600 carotenoids in the nature and it is the only one present in the macula of the eye. This lucky carotenoid is available from all the green leafy vegetables consumed by ordinary people every day. A healthy way is to take lutein by eating a nutritious meal every day, including lots of fruits and vegetables.
However, some people have no time to maintain such a balanced diet but they also want to get enough lutein every day. Nutritional supplements are a good choice for those people. It is important to strictly follow the doctor’s instructions on the dosage of these supplements and the way they are administered.
reference
·Lutein and zeaxanthin for healthy eyes
Firmoo.com is the emerging online optical store selling high quality eyewear, such as prescription eyeglasses (single vision myopic glasses, reading glasses, bifocal and progressive eyeglasses etc.,), prescription sunglasses (with RX tinted lenses), prescription sports goggles. Firmoo guarantees lowest possible price in the market. Firmoo’s return and refund policy makes any purchase risk-free ones.
Article Source:http://www.articlesbase.com/vision-articles/vision-benefits-from-lutein-1596140.html
Read More...
Astronauts receive higher daily dose of radiation, especially on a long mission such as the future Mars flight. As a result, cataracts may occur more frequently in these professionals. Currently, NASA and the National Eye Institute have been cooperating in developing a non-invasive instrument that can be used to detect very early signs of cataracts and monitor any progression.
The Alpha crystalline proteins in the lens are thought to help the lens maintain its refractive index, which allows the lens to focus light on the retina and offer clear vision. Oxidative stress may cause some proteins to break down in the lens, resulting in damaged proteins. Once these damaged proteins and other damaged cellular substances are crossly linked, they can lead to large clumps and form opacity in the lens. This opacity can gradually interfere the eyesight when they grow large enough and become cataracts.
This new instrument is supposed to evaluate the function of Alpha crystalline proteins and measure their levels as well as changes. Originally developed for space program, this measurement method can now be used to detect early signs of protein damage caused by oxidative stress. Age-related cataract, diabetes, and some neurological diseases are closed associated with oxidative stress.
Oxidative stress can be caused by UV radiation, drugs, chemicals, smoking, dietary components as well as other environmental factors. Alpha crystalline proteins in normal level can prevent these damage proteins from aggregating into clumps. However, Alpha crystalline level will be lowered due to natural aging. As a result, cataracts may develop.
As mentioned before, oxidative stress is the original cause in the lens of cataract formation. Currently, antioxidants are widely accepted to prevent cataracts, although their capacity is also unclear. In detail, lutein and zeaxanthin are two of the antioxidants that can reduce the incidence of cataract formation. A daily supplement containing antioxidants is helpful in preventing cataracts formation. These antioxidants can be gained from vegetables and fruits.
People should also control some risk factors such as smoking, obesity and eating a diet high in refined food with high sugar content. Smoking is believed to systemically decrease antioxidants in the body. Some experts also think that visible blue light can cause oxidative damage in the retina. UV protection by wearing sunglasses or UV-blocking contact lenses is also quite necessary.
More related articles:
·Causes for various congenital cataracts
·Cataract surgery preparation and outcome
Firmoo.com is the emerging online optical store selling high quality eyewear, such as prescription eyeglasses (single vision myopic glasses, reading glasses, bifocal and progressive eyeglasses etc.,), prescription sunglasses (with RX tinted lenses), prescription sports goggles. Firmoo guarantees lowest possible price in the market. Firmoo’s return and refund policy makes any purchase risk-free ones.
Article Source:http://www.articlesbase.com/vision-articles/ways-to-prevent-cataracts-formation-1534227.html
Read More...
Toxicologist John Draize, 65 years ago, invented the “rabbit test” as a standard for measuring eye damage when exposed to chemical agents. The rabbits are held in a brace preventing them from moving their bodies or heads for 21 days or longer after the chemical has been introduced into their eyes. The eyes are then evaluated for redness, corneal damage, structural changes and alterations in the anterior section of the eyes. The animals are then useless to the researchers since the eyes have been compromised.
This practice subjects the rabbits to pain and suffering and treats them like disposable tissues. It is a terrible, heartless method that demonstrates a total lack of respect for other living creatures that feel pain and fear as much as we do. Fortunately, there is an alternative method utilizing cow and chicken corneas from dead animals. This procedure has been approved by both the US and Europe. The dead tissues are exposed to the same irritants and studies instead of the live subjects. There is NO pain and NO suffering!
According to Thomas Hartung who is director of the Center for Alternatives to Animal Testing at John’s Hopkins University, the Draize eye test should become history as this and other alternative become available. The germ killing cleaning products no longer have to be tested on live rabbit eyes to see if they are safe.
We as humans have an obligation to safeguard the safety of animals. They are at our mercy and using them for this kind of testing shows a lack of respect for other life. We must employ methods that do not put animals at risk and expose them to pain. Only lab tests should be permitted and when safety and efficacy have been determined then human volunteers can be used. Animal testing never gives us the actual response anyway, so why torture these poor living creatures.
Dr. Jay B Stockman is a contributing editor for VisionUpdate.net, and a practicing doctor for New York Vision Associates, http://newyorkvisionassociates.com,
Article Source:http://www.articlesbase.com/vision-articles/animal-testing-a-tragic-disgrace-1433192.html
Read More...
In the United States, more than a half of the 2.5 million glaucoma patients suffer from different degrees of vision loss. Resulted from internal eye pressure (IOP) built-up and optic nerve damage, glaucoma has been the second leading cause of blindness.
From the IOP accumulation and optic nerve damage to various degrees of vision loss, there are always no obvious symptoms so that glaucoma is often called the “silent thief of sight”. One exception may happen to acute angle-closure glaucoma, which bring blurry womens vision, halos, intense eye pain, nausea or vomiting.
Tonometers can measure your IOP either by resting a small probe or sending an air puff onto your eye’s surface. IOP above 30 mmHg indicates a problem of the amount of fluid in the eye and brings a much higher risk of developing glaucoma. Special eye drops are created to keep IOP low, which is a treatment for glaucoma.
Scanning laser polarimetry, optical coherence tomography and confocal scanning laser ophthalmoscopy can be used to monitor the progression of glaucoma by setting up baselines and detecting changes. Optic damage by glaucoma may bring blind spots, so that visual field tests can also be used to monitor glaucoma. And ophthalmoscope can be used to view your eye’s internal structures.
There are mainly two types of glaucoma: acute angle-closure glaucoma and chronic or primary open-angel glaucoma. Chronic glaucoma has no obvious symptoms during its process of decreasing your peripheral vision. The result is that you can only see objects straight ahead. Unlike primary open-angle glaucoma, another form of open-angle glaucoma has normal IOP level, which is called normal-tension glaucoma. This type of glaucoma has no other different features with primary open-angle glaucoma. Also called narrow angle glaucoma, angle-closure glaucoma brings unexpected symptoms such as eye pain, headaches, halos, red eye etc… These symptoms appear in certain periods.
Besides the above types of glaucoma, there are still other variations. Pigmentary glaucoma is caused by iris pigment deposits and clogs the draining angles. This form of glaucoma also has no clear symptoms. Secondary glaucoma is always associated with infection, inflammation or an enlarged cataract. Infants may be born with congenital glaucoma due to natural narrow angles. Parents should take good care of their babies’ eyes, in case of congenital glaucoma signs such as cloudy, white or hazy eye.
Eye drops with medication are used to control glaucoma by bringing down IOP. Careless use of these eye drops may bring higher risks of vision loss. Further treatments include glaucoma surgery, lasers and medications.
Article Source:http://vision.firmoo.com/eye-diseases/types-of-glaucoma-and-diagnosis.html
Vision Library is the information source in area of vision care, including eyeglasses, sunglasses, contact lenses, sports protective eyewear, vision error and diseases, vision surgery, ageing and kid’s vision etc., solely sponsored by Firmoo.com, an emerging online optical store offering high quality eyewear at the lowest prices.Firmoo’s return and refund policy make any purchase risk-free.
Article Source:http://www.articlesbase.com/vision-articles/types-of-glaucoma-and-diagnosis-1399834.html