Four eye diseases account for most cases of blindness and low vision among adults living in developed nations: age-related macular degeneration, diabetic retinopathy, glaucoma and cataracts. If detected early enough, most can be successfully treated.

Eye infections and inflammations could be a telltale sign that something is amiss with your immune system or that an autoimmune disease exists.

1. Glaucoma

Glaucoma is an eye disease that attacks the optic nerve, the pathway between your eyes and brain, by increasing intraocular pressure due to fluid buildup in the eye. Glaucoma is the second-leading cause of blindness and could eventually lead to permanent vision loss if untreated properly; often developing without symptoms and unnoticed until irreparable damage has already been done, it should therefore be monitored through regular eye exams in order to remain vigilant against irreparable damage occurring due to Glaucoma.

Glaucoma comes in two main varieties: Open-angle and Closed-angle. Our eyes produce fluid constantly, but when its drainage area becomes blocked or clogged up it can stay inside our eyeballs longer, increasing eye pressure and damaging optic nerves causing loss of vision in peripheral (side) vision or eventually leading to blindness. Most common form is open-angle glaucoma which often develops slowly without noticeable visual symptoms at first.

Closed-angle glaucoma (also referred to as acute closed-angle glaucoma) often develops more quickly than open-angle glaucoma, as the drainage angle between cornea and iris becomes narrower over time, restricting fluid drainage from within the eye, leading to sudden increases in eye pressure accompanied by headaches, blurred vision, rainbow halos around lights, nausea/vomiting/redness of eyes and reddening. While more likely seen among adults over 60 but infants/young children may also develop this condition.

Glaucoma cannot be cured, but you can prevent further vision loss through regular eye exams and medications such as Beta-blockers, Alpha-adrenergic agonists and Prostaglandin analogs. Surgery may also help improve fluid flow and decrease eye pressure in closed-angle glaucoma patients. You should seek medical advice immediately if you experience severe pain in either eye, rapid vision loss, blurred or tunnel vision or redness around the eye – early diagnosis could allow medication or surgery control options to help control it effectively.

2. Diabetic Retinopathy

Diabetes damages blood vessels throughout the body, including retina (light-sensitive tissue that lines the back of each eye). Over time these blood vessels weaken and leak fluid or form scar tissue; damaging retina and impairing ability to detect visual images transmitted from outside source – leading eventually to blindness among diabetics; this is one leading cause of blindness for these individuals but regular eye exams and treatment can prevent blindness from diabetic retinopathy.

There are two primary forms of diabetic retinopathy. Background Diabetic Retinopathy or BDR occurs when small blood vessels in the retina close or bleed, bulge outward, or form fluid-filled sacs, leading to blurry vision or even retinal detachments and eventual blindness.

Proliferative diabetic retinopathy (PDR) is another form of diabetic retinopathy, whereby retinal blood vessels begin to close or bleed due to inadequate oxygen supply to the eyes, and new blood vessels form both within the retina itself as well as the vitreous gel-like substance that fills up the center of each eyeball. Unfortunately, these fragile blood vessels bleed or rupture easily, leading to blurry vision or “floaters” (dark strings or transparent spots that move across your field of view).

Untreated diabetes can rapidly worsen and eventually cause blindness; that is why regular dilated eye exams and maintaining stable blood sugar levels are crucial for good eye health.

Refractive errors are one of the most prevalent eye diseases affecting people of all ages and can be effectively managed using glasses or contact lenses. Refractive errors include nearsightedness (myopia), farsightedness and presbyopia – caused by irregularities in cornea shape or length; these errors can be corrected through glasses, contacts or refractive surgery to alter how light focuses onto retina; however, sometimes these errors are unpreventable due to natural aging processes.

3. Pterygium

Pterygium (pronounced Tur-ig’-ee-um) is a fleshy growth found on the white part of your eye that covers and spreads onto the cornea, sometimes causing irritation and blurred vision, as well as altering its shape, sometimes leading to astigmatism-inducing distortions in corneal shape and distorting its form. While noncancerous and not changing your eye color in any way, they can make wearing contact lenses difficult when large enough to obstruct pupil access.

Pterygium symptoms typically include red, swollen and itchy eyes; they may obstruct vision in bright lighting conditions and cause blurry vision; in severe cases they can progress to permanent scarring on the cornea and cause permanent vision loss – with increased risks among people who have frequent attacks or poor contact lens fits.

Pterygium’s exact cause remains unknown, though scientists believe prolonged exposure to ultraviolet radiation from sunlight plays a part. Pterygium tends to occur more often in sunny climates or among individuals who spend significant amounts of time outside; those aged 20-40 are especially prone to develop them, and having multiple pterygia increases your chances of having additional ones appear, so having them removed if they cause irritation or interfere with vision should be prioritized.

Treatment for pterygium typically includes decreasing inflammation and discomfort with artificial tears or prescription eye drops, ointments or gels; wearing sunglasses or wide-brimmed hats to block sunlight may also provide protection. In extreme cases, surgery may be required in order to eliminate symptoms that interfere with vision.

Some forms of pterygium surgery have been shown to decrease its likelihood of recurrence, such as modified bare sclera technique with conjunctival autograft, amniotic membrane transplant and peripheral lamellar keratoplasty (for advanced cases). More research needs to be conducted into which methods offer the greatest chance of improving patient quality of life while simultaneously decreasing recurrence rates.

4. Cancers of the surface of the eye

There are various forms of eye cancers that may affect eyelids, cornea and conjunctiva (the white of the eye). Any new or growing red, pigmented or white lesions should be evaluated by a physician, with biopsy being necessary in some instances if suspicious lesions emerge. Cancers of the skin that may affect eyes include basal cell carcinoma, squamous cell carcinoma and melanoma; cancers that start within eyes such as retinal cell cancer or choroid cancers being rarer still; most often seen is retinoblastoma which occurs within cells of retina cells; typically seen only children suffer from it.

Tumors may form in the orbit of the eye. This area in the skull holds the eyeball and contains muscles, blood vessels, nerve supply and fat structures that support it. Tumors may originate within this space itself or travel from other parts of the body through nerve pathways to grow there.

Any tumor or lesion near the eye should be evaluated by an ophthalmologist immediately. Most eye tumors and lesions are benign; most often caused by clogged oil glands known as chalazion or stye. Other common benign lesions found around eyelids include pterygium and pinguecula which appear as yellow patches or bulges on conjunctiva.

Pterygiums can cause eye pain, itching or watering as well as interfere with vision. They may require surgical removal. Pinchulas, on the other hand, appear as yellow deposits on the conjunctiva that thicken it further and can produce scratchy sensations or light sensitivity – these too can be surgically treated. Both conditions can be treated through medications and surgery. If pterygium or pinguecula recur after initial treatment, your doctor can suture or glue a piece of eyelid tissue over them in order to stop further growth or prescribe drugs to keep them away. If the pterygium or pinguecula is malignant, treatment options include plaque radiation therapy – using thin metal plates with radioactive seeds sewn onto one side aimed directly at the tumor site and removed after several days – or charged particle external beam therapy, using an accelerator to fire high-energy protons into your eye to destroy cancerous cells and destroy cancer.