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 ring of colored tissue around the pupil that
The lens is the clear part of the inside of the eye that helps the cornea focus incoming light on 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 located 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 illnesses can lead to blindness if left untreated.
Eye disorders and diseases cause a range of symptoms that can affect vision. Some common eye symptoms can
- blurred or cloudy vision
- double vision
- see reflections or a ring around the lights
- see floating spots
- light sensitivity
- sore or tired eyes
- difficulty concentrating on a book or computer
- lazy eye
Some symptoms will appear in childhood and others later in life. These symptoms may worsen over time and require medical treatment.
Many different conditions that can affect the eyes and vision,
Refractive errors include:
- Myopia or myopia: This is where distant objects appear blurry.
- Hyperopia or hyperopia: This makes nearby objects blurry.
- Astigmatism: Due to an abnormal curvature of the cornea, distant and near objects may appear blurry.
- Presbyopia: This is a natural and gradual loss of the ability to focus on nearby objects, usually after 40 years.
These conditions result from structural problems in the eye that prevent light from focusing properly on the retina. For example, presbyopia This is when the lens becomes stiffer with age and cannot focus light on the retina as well.
Refractive errors are generally
Age-related macular degeneration (AMD) refers to a loss of central vision that occurs with age. The problem arises when the macula, which is the central area of the retina, is damaged. AMD only affects central vision without affecting peripheral areas.
The condition can be wet or dry. Wet AMD occurs 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 progressive loss of central vision.
Cataracts are the
People can manage cataracts with new glasses or lenses, or make changes at 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.
Diabetes can damage blood vessels over time, including in the retina. The damage can cause blood and other fluids to leak, leading to swelling of the retina. The condition may not cause any symptoms at first. However, it can evolve to cause dark, floating spots or streaks and distort vision. It can also lead to more serious complications, such as detachment of the retina from the back of the eye.
Doctors may suggest laser treatment or injections to treat the condition. In severe cases, eye surgery may be necessary.
Glaucoma refers to a group of
Open-angle glaucoma is the
Doctors may suggest eye drops or laser treatment to reduce pressure on the eye. Surgery can also help drain fluid from the eye.
Amblyopia, also called lazy eye, mainly affects infants and children. The disease causes vision problems in one eye when the brain cannot process its vision properly. 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.
Treatment will usually involve wearing an eye patch over the dominant eye or using fuzzy eye drops. This will help the brain process the vision of the weaker eye and eventually balance the problem.
Other treatments may 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 imbalance, usually in infants. The condition can lead to amblyopia without treatment. Doctors may recommend glasses, contact lenses, medication, or surgery to help coordinate the eyes.