The human eye is a sensory organ that reacts to light, allowing people to see. Many eye conditions can lead to vision complications. Some eye problems are minor and may go away on their own or are easily treatable. However, some eye disorders and diseases are more serious and can lead to blindness.

The eye is very complex and contains various tissues and structures that work together to provide vision. Many types of eye disorders and diseases can affect vision and may lead to blindness.

This article discusses some common eye disorders and diseases and how to prevent them.

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The eyes work by allowing light to pass through the pupil to reach the retina, a thin layer of tissue at the back of the eyeball.

The iris is a colored ring of tissue around the pupil that controls how much light enters the eye.

The lens is the clear part of the inner eye that assists the cornea in focusing incoming light onto the retina. The retina contains light-sensitive receptor cells that convert light into electrical signals.

These signals travel to the brain through the optic nerve, a thick bundle of nerve fibers behind the eye. The brain processes these electrical signals and converts them into visual images.

Eye disorders and diseases can affect any part of this process to cause vision problems. Some diseases can lead to blindness if left untreated.

Eye disorders and diseases cause a range of symptoms that may affect vision. Some common eye symptoms can include:

  • blurred or cloudy vision
  • double vision
  • seeing glare or a ring around lights
  • seeing floating spots
  • sensitivity to light
  • headaches
  • sore or tired eyes
  • difficulty focusing on a book or computer
  • lazy eye

Some symptoms will emerge in childhood and others in later life. These symptoms can worsen over time and may require medical treatment.

Many different conditions that can affect the eyes and vision, including:

Refractive errors

Over 150 million people in the United States have a refractive error, and they are the most common vision problem.

Refractive errors include:

  • Nearsightedness or myopia: This is where distant objects look blurry.
  • Farsightedness or hyperopia: This causes close objects to look blurry.
  • Astigmatism: Due to an abnormal curvature of the cornea, distant and near objects may look blurry.
  • Presbyopia: This is a natural and gradual loss of the ability to focus on nearby objects, typically after 40 years old.

These conditions result from structural problems with the eye that prevent light from focusing correctly on the retina. For example, presbyopia is when the lens becomes more rigid with age and cannot focus light on the retina so well.

Refractive errors are usually treatable with corrective glasses or contact lenses. Some people may be eligible for surgery to change the shape of the eye. For example, laser eye surgery can fix problems with the cornea to help focus light properly.

Age-related macular degeneration

Age-related macular degeneration (AMD) refers to a loss of central vision that occurs with age. The problem occurs when the macula, which is the central area of the retina, is damaged. AMD only affects central vision without affecting the peripheral areas.

The condition can be wet or dry. Wet AMD happens when the growth of blood vessels under the macular area causes rapid loss of central vision, and dry AMD occurs when the macular thins due to aging and causes gradual loss of central vision.

There is currently no cure for dry age-related macular degeneration. However, doctors may treat wet cases with injections of medicine into the eye, laser treatment, or a combination of both.


Cataracts are the leading cause of decreased vision in the U.S. Cataracts cause a cloudy area in the lens that can blur vision. They worsen with age and can eventually lead to vision loss without treatment.

People can manage cataracts with new glasses or contacts or make changes around the home and at work, such as brighter lights. However, doctors may suggest surgery to replace the clouded lens with an implant and restore vision in more severe cases.

Diabetic retinopathy

Diabetes can damage blood vessels over time, including in the retina. The damage can cause blood and other fluids to leak, leading to swelling in the retina. The condition may cause no symptoms at first. However, it can progress to cause dark, floating spots or streaks and distort vision. It can also lead to more serious complications, such as the retina becoming detached from the back of the eye.

Doctors may suggest laser treatement or injections to treat the condition. In severe cases, eye surgery may be necessary.


Glaucoma refers to a group of eye diseases that damage the optic nerve and cause vision problems and blindness. It is usually the result of fluid building up in the eye and putting pressure on the optic nerve.

Open-angle glaucoma is the most common type of glaucoma in the US. This is where the fluid fails to drain properly from the eye. It may cause no symptoms at first, but it can lead to vision loss over time. This will often start with the peripheral vision and close in.

Doctors may suggest eye drops or laser treatment to reduce pressure on the eye. Surgery can also help to drain fluid from the eye.


Amblyopia, also known as lazy eye, mostly affects infants and children. The condition causes vision problems in one eye when the brain cannot properly process vision from it. There are many possible causes of amblyopia, such as a refractive error or cataract. If caught early, a person can receive treatment to prevent amblyopia.

The treatment will typically involve wearing an eye patch over the dominant eye or using blurring eye drops. This will help the brain to process vision from the weaker eye and eventually balance out the problem.

Other treatments might be helpful when there is a specific cause, such as glasses to correct a refractive error or surgery for a cataract.


Strabismus is where a lack of coordination between the eyes can cause them to become unbalanced, typically in infants. The condition can lead to amblyopia without treatment. Doctors might recommend glasses, contact lenses, medications, or surgery to help coordinate the eyes.

The National Eye Institute suggests some tips to protect the eyes and prevent or reduce vision loss that include:

  • getting a comprehensive dilated eye exam to check for any problems
  • being aware of risk factors, such as obesity or a family history of eye disease
  • following a healthy diet that is rich in dark, leafy green vegetables
  • quitting smoking
  • exercising regularly
  • wearing sunglasses to protect eyes from the sun
  • wearing safety goggles and glasses when there is a risk of eye damage, such as playing sport or construction work
  • taking breaks from focusing on something nearby every 20 minutes by staring at something 20 feet away for 20 seconds
  • following basic hygiene steps to avoid eye infections, such as washing hands

Some eye problems may not be apparent at first, but the symptoms can worsen over time. Anyone with symptoms of an eye disorder or disease should contact a doctor or eye specialist for an examination.

Common eye problems become more likely with age. Older adults should aim to get regular eye tests to identify any issues as early as possible.

Eye problems typically refer to any condition that affects the eyes and vision. Some problems are a natural consequence of aging, but others could result from eye damage or another underlying condition.

Anyone concerned about their vision should contact a doctor or eye specialist. Following a healthy lifestyle and having regular eye check-ups can help to prevent eye problems from occurring.