1. The cornea is the clear outer layer of the eye, covering the iris and pupil. The cornea is so transparent that it’s almost invisible.
2. The cornea provides about 2/3 of the eye’s total optical power. A healthy cornea is essential for good vision, as even a small amount of damage to the cornea can significantly affect vision.
3. The cornea is avascular, meaning it contains no blood vessels. The cornea can be thought of as more resistant to infections than other parts of the eye because it has no blood vessels.
4. The cornea is made up of 5 distinct layers, including the epithelium, Bowman’s layer, the stroma, Descemet’s membrane, and the endothelium.
5. The cornea has a high number of nerve endings, making it one of the most sensitive tissues in the body.
6. The cornea is an important part of the eye’s immune defence system.
7. The cornea can be transplanted from one person to another without extensive use of immunosuppressive drugs.
8. The cornea has the ability to regenerate itself, but the process can be slow. The cornea is often used for research on wound healing and regenerative medicine.
9. Contact lenses can be made from materials that mimic the structure and function of the cornea.
10. The cornea helps to reduce glare and protects the eye from harmful UV rays. A damaged cornea can cause significant vision loss, and corneal transplant surgery may be needed to restore vision.

Have you ever wondered about the structures that make up the eyeball and allow us to see? Let’s start at the front of the eye and work our way back.

The Cornea: 

The clear layer covering the front of the eye that lets the light get through. It has 5 layers, which can be susceptible to disease. An example is Keratoconus, when the cornea becomes “cone-shaped”. Contact lenses are placed over the cornea to help with guiding light towards the retina to allow you to see. 

The Iris: 

The colourful, circular muscle that expands and contracts to control the amount of light that gets in. The iris has two layers – at the front, some fibrous cells collectively called the stroma, and at the back, pigmented cells. The pigment is called “melanin” which makes the iris brown and opaque, allowing it to control the amount of light passing through. This is the same pigment found in our skin, and the amount that each person has varies according to their genetics. 

People with blue eyes have no pigment at all in this front layer – this causes the fibres in the iris to scatter and absorb some of the longer wavelengths of light (i.e. red, yellow, green) that come in. More blue light is reflected back out and the eyes appear to be blue. For people with hazel or green eyes, at least one of the layers of the iris contains light brown pigment. The light brown pigment interacts with the blue light and the eye can look green or speckled. 

The Lens:

The transparent disc that changes its shape to focus on objects at different distances. It can be thought of as a magnifying glass that bends and adjusts the trajectory of light coming into the eye so that it can hit the retina and be converted to an image. Cataracts happen when the lens loses its transparency, preventing light from entering the eye. Cataract surgery involves replacing the cloudy part of the lens with a new, transparent lens. 

The Retina: 

The thin layer of tissue at the back of the eye where the photoreceptors (light-sensitive cells called rods and cones) are. It receives adjusted light from the lens. The retina has lots of blood vessels and connections with the brain through the optic nerve. It is important to keep your blood pressure and blood sugar levels controlled so that the blood vessels inside the retina do not get damaged to make you lose your vision. 

The Optic Nerve: 

This collects visual information from the retina and rapidly transmits it to the brain for processing. Each of your eyes transfers information to your brain at about the same speed as a fast ethernet connection cable. 

There are approximately 8 billion people in the world. According to the WHO, globally, at least 2.2 billion people have a near or distance vision impairment. In at least 1 billion of these cases, vision impairment could have been prevented or has yet to be addressed. The demand for eye healthcare is on the rise globally, and it is becoming increasingly important to address the need for stronger eye healthcare services in developing countries. The demand for eye care services is driven by several factors including the increase in non-communicable diseases (e.g. diabetes, high cholesterol, high blood pressure) and an aging population. An aging population is one of the primary drivers of the increasing demand for eye healthcare. As people age, the risk of developing eye diseases such as age-related macular degeneration (AMD), cataracts, and glaucoma increases. These conditions can lead to vision loss and blindness, which can greatly impact an individual’s quality of life.

The growing awareness of eye health among the general public has also contributed to the demand for eye care services. People are becoming more aware of the importance of maintaining good eye health and are taking proactive measures to prevent eye diseases. This includes regular eye exams, healthy lifestyle choices, and the use of protective eyewear.

However, despite the growing demand for eye healthcare, access to eye care services remains limited in many developing countries. This is due to a lack of infrastructure, trained eye care professionals, and financial resources. This creates a significant disparity in eye care access between developed and developing countries, and it is having a major impact on the health and well-being of populations in developing countries. In developing countries, many people lack access to basic eye care services, such as eye exams, treatment for common eye diseases, and corrective vision devices such as eyeglasses. This results in preventable vision loss and blindness, which can have a significant impact on an individual’s quality of life, as well as their ability to work and participate in society. In addition, a lack of access to eye care services can lead to a vicious cycle of poverty and poor health, as people with vision loss or blindness are often unable to work and support themselves and their families.

To address the need for stronger eye healthcare services in developing countries, it is crucial to invest in eye care infrastructure and to train eye care professionals. This includes building eye care clinics and hospitals, and providing training and support to eye care professionals, such as optometrists and ophthalmologists. The Aravind Eye Hospitals in India are a strong example of how high-quality eye healthcare services can established and effectively run in developing countries. It has had a major impact in eradicating cataract related blindness in India. The Aravind Eye System recently expanded to Nigeria in 2018, where it manages the Tulsi Chanrai foundation.

In addition, it is important to provide access to essential eye care services, such as eye exams, treatment for common eye diseases, and corrective vision devices such as eyeglasses. This can be accomplished through initiatives such as outreach programs, mobile eye clinics, and partnerships with local communities. An example of a successful outreach programme is the Eyes2Eyes Scleral Lens programme, which was launched in June 2021.

It is also important to raise awareness about eye health and to promote healthy lifestyle choices. This includes educating the public about the importance of regular eye exams, and promoting healthy habits such as maintaining a healthy diet, avoiding smoking, and wearing protective eyewear. By raising awareness about the importance of eye health, people can take proactive measures to prevent eye diseases and maintain good eye health. As an organisation, Eyes2Eyes is dedicated to raising awareness about eye health and conditions, and improving access to high-quality eye care, especially for problems affecting the cornea in younger people, in the Western Cape.

To summarise, the demand for eye healthcare is increasing globally, driven by ageing, increase in non-communicable diseases and growing awareness of eye health among the general public. It is becoming increasingly important to address the need for stronger eye healthcare services in developing countries through investments into training, providing access to essential eye care services, and raising further awareness about eye health.