What are the Most Common Eye Disorders?

Wednesday 13 January 2021
Eye Disorders

Medically reviewed by

Dr. Nick Ho, MD
on 9 February 2021

Table of Contents


I. How Does the Eye Function?

II. Why Do Eye Problems Occur?

III. Understanding Glaucoma

a. Symptoms of Glaucoma

IV. Cataracts Overview

a. Symptoms of Cataracts

V. Allergic Conjunctivitis

a. Symptoms of Eye Allergies


How Does the Eye Function?

Many of us may not realize how much we rely on our eyesight until we experience vision problems. The eyes are small organs but incredibly complex. Because there are so many delicate functions, several things may go wrong with our eyes as we age. To fully understand eye conditions, it is essential to examine how the eye works.

From the minute we wake up in the morning, our eyes are working on translating the world around us. The dome-shaped, clear front layer of the eye is called the cornea. The cornea helps the eye focus, and the light goes through it to reach a small opening called the pupil. Once through the pupil, light passes through the lens to focus light on the retina. The retina possesses special cells that turn light into electrical signals. These signals then travel to the optic nerve and up to the brain, where light is processed into images. [1]

Many eye problems like cataracts and glaucoma are related to aging. Allergies and other factors may also cause more common reactions like itchy and watery eyes. Patanol (olopatadine) and Zaditor eye drops can be used to relieve symptoms of allergies. You may be prescribed Azopt (brinzolamide), Lotemax (loteprednol), or Zymar Opthalmic Solution for more severe eye problems like cataracts and glaucoma. 

a viewfinder at the top of a hill

Why Do Eye Problems Occur?

Like many medical disorders, eye problems can occur for a myriad of reasons. It is recommended that people get yearly eye exams to ensure that their eyes are healthy and working properly. Genetics play a major role in the majority of vision problems among children and adults. Eye problems are present in one-third of inherited diseases. [2]

All of our body parts age along with us and the eyes are no exception. Around one in three peoplover the age of 65 have some form of vision-reducing eye disease. Macular degeneration and glaucoma are the most common age-related eye problems. Losing your vision is a major disability and can severely affect the everyday habits of older people. [3] 

Throughout the year, seasonal allergies come and go. Some people are allergic to certain blooming plants and trees in the spring, causing allergic conjunctivitis. Indoor and outdoor irritants can plague some people all year round, especially if you live with animals that shed dander or live around smoke and chemicals. [4]

Understanding Glaucoma 

Glaucoma is made up of several different eye conditions that involve damage to the optic nerve. The optic nerve is essential for good vision and may be damaged by abnormally high pressure in the eye. Glaucoma is a leading cause of blindness and typically affects older adults. This eye condition usually has no warning signs, and symptoms may only occur once the eye is already damaged. 

Over time, the optic nerve may gradually deteriorate and cause blind spots in your vision. When this nerve is damaged, pressure in the eye increases and causes a buildup of fluid. Normally, this fluid flows through the eye at the angle where the iris and cornea meet. With glaucoma, this fluid cannot drain properly and increases eye pressure. Azopt (brinzolamide) may be prescribed to assist in the symptoms of glaucoma. The types of glaucoma include: 

  • Open-angle glaucoma
  • Angle-closure glaucoma
  • Normal-tension glaucoma
  • Pigmentary glaucoma [5]

a close up of an older person

a. Symptoms of Glaucoma

Your symptoms may depend on the type of glaucoma you are experiencing. Open-angle glaucoma occurs when ocular fluid cannot drain correctly and may cause:

  • Patchy blind spots in the peripheral or central vision (usually in both eyes)
  • Tunnel vision if the glaucoma is advanced

Angle-closure glaucoma may occur suddenly (acute) or slowly over time (chronic). With this type, the iris bulges forward and blocks the angle where fluid drains from the eye. It may cause:

  • Severe headache
  • Blurred vision
  • Eye redness
  • Seeing halos around lights
  • Nausea and vomiting
  • Eye pain [5]

Cataracts Overview 

Unlike glaucoma, cataracts involve visible physical changes to the eye. Cataracts create cloudy and dense areas in the lens of the eye. Cataracts occur when proteins in the eye form clumps that create a milky appearance. Cataracts are also common in older adults because they develop slowly over time to interfere with vision. 

Around half of the people in the United States have cataracts or have had cataract surgery before the age of 80. Along with age, other causes of cataracts can include smoking, trauma, and certain diseases like diabetes. After cataract surgery, you will likely be prescribed medications like Zymar Opthalmic Solution or Lotemax (loteprednol) to prevent eye infection. [6] 

a. Symptoms of Cataracts 

Cataracts sometimes have symptoms before the milky appearance of the eye occurs. If you experience the following symptoms, talk to your ophthalmologist: 

  • Trouble seeing at night
  • Double vision in the affected eye
  • Increased sensitivity to glare
  • Colors appear faded
  • Blurry vision
  • Need for frequent changes in prescription glasses [6]

Allergic Conjunctivitis 

The tissue that lines the eyelid and outside of the eyeball is referred to as the conjunctiva. The conjunctiva may become inflamed due to allergies and cause several unpleasant side effects. Redness and itching in one or both eyes is referred to as allergic conjunctivitis. 

a gray pitbull looking at the camera

This eye problem occurs when the body has an allergic reaction to an irritant and creates histamines to respond to the inflammation. The eyes are often the target of irritants because they are exposed to the elements and innately sensitive. Allergic conjunctivitis can be caused by: 

  • Viruses
  • Bacteria
  • Pollen
  • Mold spores
  • Dust mites
  • Pet dander [4] 

a. Symptoms of Eye Allergies

If your eyes are irritated by one of the above irritants, one or both eyes can be affected. It is not a serious condition but can be very bothersome and affect everyday activities. If your symptoms are severe, you may be prescribed Patanol (olopatadine) or Zaditor eye drops. Common symptoms of eye allergies include: 

  • Watery eyes
  • Swollen eyelids
  • The sensation of dirt or grit in the eyes
  • Itchiness
  • Redness [4]

If you are experiencing eye issues of any kind, there is no harm in getting an appointment with your eye doctor. Talk to your doctor to determine the best form of treatment for your eye disorder. 

The content in this article is intended for informational purposes only. This website does not provide medical advice. In all circumstances, you should always seek the advice of your physician and/or other qualified health professionals(s) for drug, medical condition, or treatment advice. The content provided on this website is not a substitute for professional medical advice, diagnosis, or treatment.