Refractive errors
A refractive error represents the most prevalent issue concerning vision. When the eye’s shape is irregular, it fails to bend (or refract) light correctly, resulting in blurred vision.
The most common types of refractive errors are:
- Long-sightedness (hypermetropia) – causing blurred close and distance vision.
- Short-sightedness (myopia) – causing blurred long-distance vision.
- Astigmatism – causes an uneven focus of light and blurred vision.
- Presbyopia – the eye lens loses flexibility, making close work difficult. This is most common with people over 40 years of age.
These errors can be corrected with glasses or contact lenses.
Cataracts
A cataract refers to the clouding of the eye’s lens. Typically, the lens is transparent. Cataracts may affect one eye or both. While cataracts primarily develop in older individuals, they can also occur in younger people, and in rare instances, infants may be born with a cataract, known as a congenital cataract.
Initial cataracts can be detected during an examination by an optometrist or ophthalmologist, and optimal vision may be attained by modifying the prescription of prior distance glasses.
In the early stages, cataracts may occur simultaneously with the requirement for distance glasses for the first time in approximately 30% of individuals over the age of 60. For these individuals, cataract surgery might not be required for several years, as new glasses can offer adequate visual clarity.
Cataract surgery becomes essential only when, even with the use of suitable glasses, the cataracts hinder daily visual activities such as reading, driving, engaging in hobbies, and ensuring safe mobility.
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There are infrequent instances where cataract surgery is necessitated by other eye health issues, including narrow angles in the eye and discrepancies in glasses prescriptions between the two eyes.
Diabetic eye disease
Diabetes can impact your vision in various manners. Therefore, it is crucial to undergo a thorough eye examination immediately upon receiving a diabetes diagnosis, and to subsequently maintain regular eye check-ups.
It is essential to maintain these regular appointments, even in the absence of noticeable symptoms. The most effective method to avert vision loss is through early detection and treatment.
The retina is a layer of light-sensitive tissue located at the inner back of the eye. In individuals with diabetes, the retina may gradually sustain damage, leading to vision issues.
This condition is referred to as diabetic retinopathy, which can result in irreversible visual impairment if not detected and treated promptly.
The longer one has diabetes, the greater the likelihood of developing diabetic retinopathy.
Additionally, your risk escalates if your diabetes is poorly managed or if you suffer from high blood pressure or elevated cholesterol levels.
Macular degeneration
Age-related macular degeneration (AMD) is a chronic and painless condition affecting the macula. The macula is located at the center of the retina, situated at the back of the eye.
AMD leads to a gradual decline in central vision. However, it preserves peripheral vision. This decline in central vision can hinder activities such as reading, watching television, and recognizing faces. On its own, AMD does not result in complete vision loss (total blindness).
For some individuals, AMD progresses very slowly and may not affect their vision significantly. Conversely, for others, AMD can advance more rapidly, resulting in vision loss in one or both eyes.
If you are diagnosed with AMD, it is crucial to regard any sudden changes in your vision as a medical emergency. Seek immediate attention from an optometrist or ophthalmologist.
Glaucoma
Glaucoma refers to a collection of eye disorders that result in vision impairment due to damage to the optic nerve. This condition leads to irreversible vision loss as a consequence of optic nerve damage. Typically, the deterioration of sight occurs gradually, and a significant portion of peripheral vision may be lost before any issues are recognized.
Regrettably, there is no available cure for glaucoma, and once vision loss occurs, it cannot be reversed. If not addressed, glaucoma progressively leads to irreversible vision loss and potential blindness.
The sole method for managing glaucoma is to adhere to the treatment plan prescribed by an eye care specialist. These treatments can help prevent additional vision loss. At present, the only recognized treatment for glaucoma involves reducing intraocular pressure to a safe level.
Regular follow-up appointments are essential for effective management of glaucoma.
Retinal detachment
Retinal detachment occurs when the tissue layer located at the back of the eye (the retina) becomes separated from the eyeball. This condition is more prevalent among individuals who are nearsighted.
This constitutes a medical emergency. The retina is responsible for your vision. If it sustains damage, you may experience vision loss. The symptoms of a detached retina include:
- light flashes and/or moving specks or cobwebs (floaters) from one eye
- Sudden loss of or change in vision – like a curtain pulled over their eye, or a shadow
- blurred vision or seeing an empty circle in front of you
- changes to peripheral vision
If you suspect that you are experiencing retinal detachment, please proceed to an emergency department without delay.
Corneal ulcer
A corneal ulcer refers to an open sore located on the cornea, which is the transparent dome that protects the colored iris of the eye.
Corneal ulcers are frequently the result of infections, particularly those that occur following a physical injury to the cornea.
Symptoms may consist of a red, irritated, and painful eye, a sensation of a foreign body, blurred vision, and discharge.
Prompt medical intervention for a corneal ulcer reduces the likelihood of enduring damage to your vision.
Eye discharge
Discharge from the eyes could indicate the presence of an eye infection. Such infections may arise from various factors.
Common eye infections include:
- conjunctivitis
- blepharitis
- styes
- scratches or irritations caused by allergies to pollen, dust or smoke can also cause a discharge from your eyes
Blepharitis
Blepharitis refers to the inflammation of the edges of the eyelids. Typically, both eyes are involved. This condition manifests in two types: anterior (or front) and posterior (or back) of the eyelid edges.
The primary cause is a bacterial infection affecting the glands of the eyelids and the follicles of the eyelashes. Blepharitis can develop in individuals of all ages, including children and adults. The signs and symptoms associated with this condition include:
- a feeling of “something in the eye”
- excessive or frothy tears
- itchiness
- excessive blinking
- photophobia (sensitivity to light)
- crusty or sticky eyelashes, particularly in the morning
Conjunctivitis (pink eye)
Conjunctivitis, commonly referred to as ‘pink eye’, is a condition characterized by the pink or red discoloration of the white part of the eye. This occurs as a result of inflammation of the eye’s transparent outer layer, known as the conjunctiva, as well as the inner surface of the eyelid.
Conjunctivitis has the potential to be highly contagious, making it essential for a doctor, optometrist, or pharmacist to accurately diagnose the underlying cause to ensure appropriate treatment is administered.
In cases of bacterial conjunctivitis, there is often a yellow or green discharge from the eyes, which may cause the eyelids to adhere together. This condition can affect one or both eyes.
Conversely, in instances of viral or allergic conjunctivitis, the discharge is typically clear. Additionally, one may experience symptoms associated with hay fever, such as an itchy nose and sneezing.
Stye
A stye is a small, painful cyst located on the eyelid. It is typically caused by a bacterial infection at the base of an eyelash follicle.
The stye may feel sore and tender, potentially obstructing part of your vision until it resolves. Generally, styes will heal on their own within 1 to 3 weeks, without the need for treatment.
Uveitis
Uveitis refers to the inflammation occurring within the eyeball. This condition affects the uvea, which is a layer of blood vessels located inside the eyeball, beneath the sclera, or the white part of the eye.
Uveitis may result in symptoms such as redness, pain, floaters, light sensitivity, and blurred vision. In severe instances, it has the potential to harm the eye tissue and result in blindness.
Squint (strabismus or turned eye)
A squint, also known as strabismus, denotes a misalignment of the eyes. There are various types of squint; however, they can generally be categorized into the following groups:
- esotropias, where one eye turns in towards the nose
- exotropias, where the one eye turns outwards
- hypertropias and hypotropias, where one eye is higher (hypertropia) or lower (hypotropia) than the fellow eye.
Blocked tear ducts
Tears are produced to maintain moisture in the eye. Typically, they drain through a small opening located near the nose, found on both the upper and lower eyelids. Subsequently, they pass through a slender tube known as a tear duct before being expelled into the nose. This explains why your nose may run when you cry.
Approximately 1 in 20 infants are born with a blocked tear duct. This condition may arise if the duct is not fully developed or is excessively narrow, leading to a blockage.
Adults can also experience blocked tear ducts, often due to an infection. Other causes may include injuries and, on occasion, certain medications.
Keratoconus
Keratoconus is a condition of the eye that impacts the cornea, which serves as the transparent front surface of the eye.
Keratoconus arises when the cornea gradually alters its shape. While a healthy cornea typically has a dome-like form, in cases of keratoconus, it thins and takes on a conical shape. This alteration affects how the eyes focus light and can lead to visual distortion.
Keratoconus generally manifests in younger individuals, typically between the ages of 16 and 30, and continues to progress until around the age of 40. It often affects both eyes, although one eye may be more severely impacted than the other. If you observe any symptoms related to your eyes or notice changes in your vision, it is advisable to consult your optometrist or physician.
Twitching eye
The terms ‘twitching eye’ and ‘eye twitch’ refer to involuntary muscle spasms occurring in the eyelid. Generally, these spasms are mild and resolve independently. A twitching eye occurs when the eyelid muscles contract (spasm) involuntarily.
Numerous factors can cause eye twitches, including:
- stress
- fatigue
- bright lights
- irritation of the eye or inner eyelids
- smoking
- pollution
- excess caffeine or alcohol.
Eye twitches may persist for over a week or escalate in severity, particularly when the eyelid shuts for several seconds. Consult your physician if they endure beyond one week or if they intensify and are accompanied by additional symptoms.
Colour blindness
If you have color blindness, your perception of colors will differ from that of the majority of individuals.
Color blindness is a prevalent condition that can be diagnosed with ease and may not significantly impact your life.
