The white part of the eye referred to as the sclera is the strong tissue that surrounds the eyeball. It is due to the sclera that the shape of the eyeball is maintained and also protects against eye injuries. Several instances can make the sclera change the color, or cause spot color changes. Discolored sclera can resolve within a few weeks, but can be serious in several situations and must be medically addressed.
What is sclera and what does it do?
It is the white portion of the eye that extends from the cornea in the front to the optic nerve situated in the back. The protective layer of the tissue, less than a millimeter in thickness, gives the eyeball a distinct white color. The sclera has the reputation of protecting and supporting the eye.
The primary function of the sclera is supporting the eyeball walls. It is responsible for maintaining the right shape of the eyeball and also protects from serious injury. The sclera is encrusted by conjunctiva, consisting of clear mucus membranes. The function is to moisturize and lubricate the eyes. The muscles attached to the sclera aid in moving the eyeball side to side and up and down.
Understanding the anatomy of the sclera
Before gaining knowledge of the conditions and disorders that gives rise to the discolored sclera, a basic understanding of the anatomy of the sclera is important. The sclera consists of tough collagen fibers positioned in random directions. It is this random pattern that gives white color to the eyeball and the required strength to the sclera. Therefore, there is a contrast with the cornea collagen fibers, which are in an organized pattern and render a clear cornea. The sclera consists of four layers positioned from the outside to the inside.
1. Episclera is the clear and thin tissue that lays on the top portion of the whites of the eyeballs.
2. The stroma consists of collagen fibers and fibroblasts and thereby blends into the episclera.
3. The third layer is the transitional layer (lamina fusca) which is positioned between the sclera and the ciliary and choroid bodies.
4. The endothelium is the innermost layer of the sclera.
Conditions and disorders impacting the white color of the sclera
Several conditions can cause the discoloration of the white sclera completely or render some color spots on it.
Blue sclera
When the sclera is comparatively thinner than usual, the blood vessels appear. This gives the eyeball a blue or gray hue. Such a situation arises when individuals suffer from certain health issues like Marfan syndrome, osteogenesis imperfecta, anemia, iron deficiency, and so on.
Jaundice
When the sclera turns completely yellow, it indicates the person is suffering from severe jaundice. Jaundice is the condition that notifies that the liver isn’t functioning properly and not filtering blood optimally. When discolored sclera is indicative of jaundice, treatment must be started at the earliest to prevent damage to the liver functioning.
Injury
When eyeballs get injured badly, one might notice bright red spots. This shows that there is a broken blood vessel that has blood leaks. The red spots are not harmful and resolve within a few days to weeks. In the case when the red spots don’t go away or increase one has to understand that the situation is grave and must be medically attended to.
Medication
Certain medications like antibiotics can cause a bluish or grayish tint on the sclera. It is usually harmless, but it is always better to keep the doctor updated about the situation.
Eye irritation
Due to several reasons like infection, allergies, smoke, exhaustion, etc., eyes can be irritated. When one suffers from eye irritation, the sclera becomes bloodshot and there is redness. It is recommended that one mustn’t press the eyes or squeeze them as it increases the irritation and discomfort of the eyes.
Melanosis
Often people with brown and black skin are found to have flat brown spots similar to freckles on their scleras. The spots are harmless and are caused due to high pigment levels, called melanin.
Pinguecula and pterygium
Due to damage from the sun, severe wind, or dust, one might experience a bulge of yellow patches on the sclera. This condition is referred to as pinguecula, and when inflamed might turn pink or red. Pterygium is the growth of the fleshy tissue that expands into the cornea of the eyes and turns the sclera into red color. If the condition goes untreated, the vision will be impacted.
PAM
When one has a flat brown spot on the eyes over a period, gradually changing over time, it refers to the condition known as Primary Acquired Melanosis, PAM. It might be cancerous, and thereby highly recommended to consult a professional doctor in case of changing color or appearance of new spots on the sclera.
When to seek medical attention?
Anything different that one notices in the sclera, must be addressed to the doctor. Some of the situations are:
· Discolored sclera
· Blurry vision
· Vision loss
· Bulging sclera
· Change in the existing spot on the sclera (changing of spot color, new appearance, or spots becoming larger)
· Puss or fluid oozing out of eyes
· Eyeball swelling
· Light sensitivity
Protecting the sclera
Certain simple strategies can help protect the sclera and prevent the sclera from getting inflamed or injured.
· Wearing safety goggles while playing outdoor sports or rendering any repairs.
· Wearing UV-protectant sunglasses to guard the eyes against sun damage, dust, debris, and wind.
· Washing hands or sanitizing before touching the eyes can prevent infections.
Conclusion
The sclera is the protective wrap that covers the majority of the eyeball and gives the distinct white color. Minor inflammation, injury, medications, and certain health conditions cause discolored sclera. In the majority of the minor cases, the discoloration goes away on its own after a certain period. In case the symptoms and other issues related to the sclera don’t resolve, one must seek the help of an ophthalmologist. Unattended issues can cause partial vision loss and in some cases blindness.