Learn about the most common eye conditions and why some of them have no early symptoms and can only be detected with an eye exam.
Amblyopia is also known as lazy eye. It occurs during the early stages of life, usually before 6 years of age. It is not a disease and it doesn’t cause blindness, but the central vision is impacted—the peripherals remain intact. This results in a poor link between the eye and the brain, causing a “lazy” eye.
When your cornea or lens is irregularly shaped (more oval than round), it causes blurred vision at every distance. This is called astigmatism. It is not a disease and clear vision can be achieved with eye glasses or contacts.
Usually incorrectly called colour blindness, colour deficiency is when you have a hard time deciphering colours and shades. It can be inherited or be the symptom of trauma or disease. Some affected individuals can’t identify red and green shades while others can’t identify blue and yellow shades.
Presbyopia is when you find it difficult to focus on objects close to you. This happens because the crystalline lens of your eye has become inflexible (for your eye to focus, elasticity is needed). Often, prescription reading glasses, bifocals, trifocals or contact lenses will correct presbyopia.
A cataract refers to the eye’s lens when it becomes cloudy in appearance, thereby impairing vision as light cannot focus on the retina to produce clear images. There are several variations of cataracts, but most are due to the lens’ chemical makeup being altered and may be a sign of disease. Three common types of cataracts are:
- Cortical cataract
- Nuclear cataract
- Posterior capsular cataract
In Canada, glaucoma is the second leading cause of blindness. It classifies a set of disorders where the eye tissue damage is at least partly caused by pressure, or sometimes called intra-ocular pressure (IOP). Early detection via regular eye exams is ideal for treating glaucoma, as the condition’s symptoms are gradual and subtle, and if not identified, glaucoma can cause blindness.
The part of your eye that illustrates fine details like face recognition is the central vision, and this is the part of the eye that is affected by macular degeneration (ARMD). With ARMD, your peripheral vision remains clear but details will not be visible. This condition is mainly caused by age; those older than 50 years are at greater risk. Genetics, smoking, exposure to UV rays, high blood pressure, diabetes, arteriosclerotic vascular disease all increase your likelihood of developing ARMD. There are 2 main types of ARMD:
- Dry (a common form of ARMD and refers to the gradual breakdown of the retina’s light-sensing cells)
- Wet (a less common form of ARMD and is caused by the growth of abnormal blood vessels that bleed, damaging central vision)
Bulging eyes, otherwise known as proptosis, occurs when one or both eyes protrude from the eye socket, due to lesions that occupy the space in your eye sockets. The most common effect of bulging eyes is that it exposes a larger percentage of the cornea to be exposed to air, making it more difficult to keep eyes moist and lubricated. Bulging eyes have been linked to a number of underlying medical conditions which often determine the overall course of treatment.
Strabismus, (crossed eyes) is a condition defined when a person’s eyes are not able to align on the same point at the same time. This usually occurs as a result of the weakness of the muscles in one or both eyes.
A young child with strabismus can unconsciously reject the image of the improperly aligned eye and the related nerve connections between their eye and brain may fail to develop. This can lead to a reduction in vision in the eye.
DME (Diabetic Macular Edema) is a complication of diabetes that is caused by the accumulation of fluid in the central portion of the eye. This causes the macula to swell which in turn causes the cells in this part of the eye to be impaired which causes blurred vision that can become quite severe.
Treatment for Diabetic Macular Edema is designed to maintain vision and reduce potential future vision loss. Treatment can include medication that is injected or implanted into the eye, as well as laser eye surgery.