Human Body: Eye and Blindness

Inquiry & Research

"Inquiry is a complex process of constructing personal meaning, applying critical thinking skills, solving problems, creating understanding, and questioning. In its truest form, the inquiry process requires and individual to look deeper and beyond the obvious, examine information for validity, point of view and bias, and construct meaning from all of these endeavours. Effective application of an inquiry model can transform novice learners into interdependent and independent learners, confident of their information power."

Ontario School Library Association (2010). Together for Learning: School Libraries and the Emergence of the Learning Commons. 

By: Rahim


About the Eye and Blindness

           The eye is a part of the body which is very important; it let’s us see the world around us. Therefore, you can imagine what it would feel like not being able to see. Imagine being blind, trying to do everyday things without one of your five senses. Blindness is a hard disability to live with. However, scientists have found ways to cure blindness, such as making bionic eyes. The problem with these mechanical eyes is they only work for a very small amount of the population, and getting a hold of one isn’t easy. For example, the makers behind the bionic eye, Argus II will be making a small quantity of them, and will be selling it for about $115,000 US. The key question then is how should we prevent blindness/visual impairment, which affects about 285 million people worldwide. (39 million people are blind and 246 million are visually impaired). 90% of the world's visually impairment/blindness cases are found in the developing countries, and 80% of all cases can be cured. (World Health Organization: Fact Sheet No 282. Updated Oct 2013).

   

How the Eye Works

           

The eye sees things when light reflects off any object you are looking at. The light and/or image goes through the clear cornea, and pupil, and into the lens. After it comes out of the lens, the light and/or image flips upside-down. The light then travels into the retina. The retina has cones and rods inside of it. Cones are color-receptive, thus, allowing us to see color. Rods are used when light around us is dim, therefore, we can see shades of black. The information is then sent from the retina, and into the optic nerve. The optic nerve transmits the information into the main visual cortex of the brain, also known as V1. The eyes and the brain work together to see. Your brain can process and recognize what you're seeing. In eyes that work correctly, this process happens almost instantly.

Amazing Facts About the Eye

Optical Illusions 

An optical illusion (also called a visual illusion) is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source. 

There are three main types:

1. Literal optical illusions that create images that are different from the objects that make them.

2. Physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, colour, size, position, tilt, movement), and 

3. Cognitive illusions, the result of unconscious inferences.

Source: Wikipedia.

Trippy Eye Tricks

10 Amazing Illusions

Origin of Eye Research

The foundation of modern optics can be traced to the research of Muslim scholars. This research revealed the mechanics of the human eye and gave rise to the first camera. They inherited two conflicting theories of vision from the Greeks; one that our eyes produce light rays which bounce off an object back into the eye, and the other, that light rays emanate from the object that we see. Neither idea had been tested through experiment. New light on the subject was shed by the pioneering work of Muslim scientists.

More details about this in the Sultans of Science exhibit at the Ontario Science Centre and video on the pinhole camera.

Sultans of Science: 1,000 Years of Knowledge Rediscovered opened Friday, March 7, and will run until June 7, 2014 for visitors to learn about the important scientific and technological discoveries made by scholars during the Golden Age of Islamic Science. 

The exhibition areas include the Foundation of Optical Science where visitors can conduct various experiments in the optical laboratory of Ibn Al-Haytham, a 10th century Muslim physicist who invented the pinhole camera. Lesley Lewis welcomed back the popular exhibit to the Ontario Science Centre in her opening remarks, which she noted coincides nicely with the scheduled opening of the Aga Khan Museum near Don Mills Road and Eglinton Avenue this year.

By Clark Kim Retrieved from http://www.insidetoronto.com/news-story/4402898-sultans-of-science-exhibit-touches-down-at-ontario-science-centre/

IBN AL-HAYTHAM: FATHER OF MODERN OPTICS

What should you do to ensure healthy eye?

• Protect your eyesight through regular eye exams
• Avoid intense ultraviolet (UV) light (wear sunglasses)
• Maintaining a healthy diet
  
  Slide Show: 11 Foods to boost your eye health by Aimee Surtenich

Diet for sustaining a healthy vision for lifetime:

• Eat whole grains and cereals. Sugars and refined white flours commonly found in breads and cereal may increase your risk of age-related eye diseases. Choose instead 100 percent whole-grain breads and cereals that have lots of fiber. 

• Make sure fats are healthy. The omega-3 essential fatty acids found in fish, flaxseed oil, walnuts and canola oil help to prevent dry eyes and possibly cataracts. Eat fish or seafood twice weekly, or take flax oil every day. Use canola oil for cooking and walnuts for snacking.

• Choose good sources of protein. Remember that fat content and cooking methods are what make proteins healthy or unhealthy. Also, avoid saturated fats from red meats and dairy products that may increase your risk of macular degeneration. Choose lean meats, fish, nuts, legumes and eggs for your proteins. Most meats and seafood also are excellent sources of zinc. Eggs are a good source of lutein. 
 
• Avoid sodium. High sodium intake may add to your risk of cataract formation. Use less salt, and look for sodium content on the labels of canned and packaged foods. Stay below 2,000 mg of sodium each day. Choose fresh and frozen foods whenever possible. 

• Stay hydrated. Round out a healthy diet with low-fat dairy products such as skim or 1 percent milk for calcium, and healthy beverages such as 100 percent vegetable juices, fruit juices, non-caffeinated herbal teas and water. Proper hydration also may reduce irritation from dry eyes.
  

By Shereen Jegtvig, Certified Nutrition Specialist (CNS). Retrieved from http://www.allaboutvision.com

When the eye does not function properly a person may be visually impaired or blind.

Visual Impairment

What is visual impairment?

Visual impairment is the consequence of a functional loss of vision, rather than the eye disorder itself. Visual impairment is a term use to describe any kind of vision loss, whether it's someone who cannot see at all or someone who has partial vision loss.

What are the major causes of visual impairment?

• Refractive errors (myopia, hyperopia or astigmatism), 43 %
• Cataract, 33%
• Glaucoma, 2%.
  

How is visual impairment treated?

• Eyeglasses or contact lens
• Medication
• Surgery
  

Blindness
 
What is blindness?

Blindness is a lack of vision. Complete blindness means you cannot see anything and do not see light. Partial blind means you have very limited vision. Legal blindness refers to vision that is highly compromised: What a person with healthy eyes can see from 200 feet away, a legally blind person can see only from 20 feet away.

What are the symptoms of blindness?

If you are completely blind, you can see nothing. If you are partially blind, you might experience the following symptoms:

• Cloudy vision
• The inability to see shapes
• Seeing only shadows
• Poor night vision
• Tunnel vision

What causes blindness?

• Glaucoma refers to four different eye conditions that damage the optic nerve.
• Macular degeneration destroys the part of your eye that enables you to see details. It usually affects older adults.
• Cataracts cause cloudy vision and are more common in older people.
• A lazy eye can make it difficult to see details and may lead to vision loss.
• Optic neuritis is inflammation that can cause temporary or permanent vision loss.
• Retinitis pigmentosa refers to retina damage, but leads to blindness only in rare cases.
• Tumors that affect the retina or optic nerve can also cause blindness.

Prevention and Control

How should we prevent and control visual impairment and blindness?

According to a recent survey done by the National Eye Institute, most Americans decided that the loss of sight would have the greatest impact in their daily living, compared to other disabilities (loss of memory, speech, arm or leg, and hearing). Most of us take our eyesight for granted until it's threatened. But there are steps you can take to make sure that your own eyes last a lifetime.

• Most blindness is preventable through timely treatment.
• Protect your eyesight through regular eye exams
• Maintaining a healthy diet

Overall, visual impairment worldwide has decreased since the early 1990s. This is despite an increase of the global elderly population. This decrease is mainly the result of a reduction in visual impairment from contagious diseases through:

• Intensive public health action
• Increased availability of eye care services;
• Awareness of the general population about solutions to the problems related to visual impairment.

The global response to prevention of blindness

Globally, 80% of all visual impairment can be prevented or cured. Areas of progress over the last 20 years include:

• Governments establishing national programs and rules to prevent and control visual impairment
• Eye care services are being increasingly put into primary and secondary health care systems, with a focus on services that are high quality, available and affordable
• Campaigns to raise awareness, including school-based education
• Stronger international partnerships
  

Specific achievements include:

• Data over the last 20 years shows that there has been significant progress in preventing and curing visual impairment in many countries. In result, there has been a massive reduction in Onchocerciasis (disease caused by parasitic worms) related blindness as part of a significant reduction in the disease. This has been achieved through a number of successful international partnerships. 


• Trachoma is the leading cause of infections blindness in the world and active in many of the poorest and most rural areas of the 53 countries in Africa, Asia, Central and South America, Australia and the Middle East. It is responsible for the visual impairment of about 2.2 million people, of whom 1.2 million are irreversibly blind. A number of countries have reported achieving intervention goals, which signify the end of the campaign to trachoma elimination and the move to on post-active surveillance. These countries are: The Gambia, Ghana, Iran, Morocco, Myanmar, Oman and Viet Nam.
   
• Over the last decade, Brazil has been providing eye care services through the national social security system.
   
• Since 2009, China has invested over 100 million dollars in cataract surgeries.
• Oman has completely integrated eye care service provision in the primary health care framework over the last decade.
• Since 1995 India has made available funds for eye care service provision for the poorest.
• Overall, Africa remains the most affected continent and the one with the most intensive control efforts. In 2012, 45 million people were treated with antibiotics and 155 thousand cases of trichiasis were operated in 29 active countries of WHO’s Africa Region.

Research: Looking for treatments and cures for blindness

One of the greatest dreams for many people with blindness and their families may be that someday there will be a cure or treatment for blindness that can restore vision to those who have lost it and/or delay any potential loss of vision. We are living in a remarkable age, and it is very likely that in the lifetime of many of our readers such a dream may become reality for many people, especially those whose vision loss is caused by certain diseases or syndromes. Most research efforts are still in the early stages using animal models; a few are beginning very limited human trials. Undoubtedly, some will prove successful and some will not, but it is exciting to learn more about what’s being done. This work falls generally into four categories:

• Genetics and Gene Therapy
• Retinal Implants and Transplants
• Pharmaceutical Therapy
• Nutritional Therapy

Some of research work includes:

First “Bionic Retina” Becomes Available

The Food and Drug Administration granted market approval for the Argus II retinal prosthesis, the first device of its kind available in the U.S. that can restore some vision to people blind from advanced retinitis pigmentosa.




Gene Therapy For Lca Closer To Fda Approval 



The landmark gene therapy study that restored significant vision in patients with Leber congenital amaurosis (LCA) has advanced to a Phase III clinical trial - one step closer to FDA market approval. In addition, more than 150 people have received gene therapy in studies underway for retinitis pigmentosa, choroideremia, Stargardt disease, Usher syndrome and macular degeneration.




Promise In Stem Cell Research 


The first-ever stem cell clinical trial targeting retinitis pigmentosa using human wide-spread stem cell-derived photoreceptors is poised to begin in 2014, aiming to rescue and preserve vision.




New Stargardt Disease Study Launched 


The Foundation’s Clinical Research Institute started a natural history study of people affected by Stargardt disease, called ProgSTAR, to help researchers gain a better understanding of the condition and to develop optimal outcome measures for forthcoming clinical trials.




           

Seed Money Blooms


Thanks to early Foundation support, two start-up biotech companies developing gene therapies for retinal diseases attracted nearly $40 million dollars each in venture capital funding to help move the treatments forward. Applied Genetic Technologies Corporation (AGTC) is targeting achromatopsia and X-linked retinoschisis, and GenSight Biologics is targeting retinitis pigmentosa.

           

 

Conclusion

            In conclusion, mankind has done many great things for the eye. All of the latest research proves it. Our bionic retinas have made a great impact to the society at large. But is that society large enough? I believe we are not making our great innovations accessible for others. For example, the Argus II has only been selling in America, and ninety percent of visually impaired are in the developing countries. Thus, only ten, or less percent are able to access this invention. Developing countries have the most of who are visually impaired; they haven’t got any cure to blindness. We have been establishing many medical centers, but no accessibility to cures for blindness, such as the Argus II. We must make it more accessible to all, or there is not much reason in doing it. As I have stated there is still ninety percent to deal with. The global response to blindness has been tremendous and many countries are actively providing health services as part of their health programs. My thoughts are the eye proactive care should be given from very early age. The education system should incorporate the healthy dietary and hygiene studies to take care of the eyes. This will impact eye disease such as trachoma that is the leading cause of infectious blindness in the world. The World Health Organization (WHO) through the support of other agencies such as International Council of Ophthalmology (ICO), International Agency for the Prevention of Blindness (IAPB should actively be involved in seeking funds and partner with national health institutions and, if possible, local eye clinics at the grass root level to promote healthy eye care programs. It is also encouraging to know that many eye doctors and specialists in Canada are giving their voluntary time to visit remote locations in the world to train and provide eye services. Its only through the partnership of the governments, private sectors, and the civil society organizations within the framework of international organization such as WHO that I think we will make a substantial impact in resolving the eye visual impairment and blindness problem worldwide.