Amblyopia (Lazy Eye)
Amblyopia or “lazy eye” describes weak vision or vision loss in one or both eyes that cannot be fully corrected with lenses.
It usually develops in children before age eight.
This is also the key time to treat amblyopia, since results are better the earlier they are implemented.
It becomes extremely difficult to treat amblyopia after age eight.
Amblyopia is more than simply an eye health problem.
It involves the “wiring” of the nerve impulses from the eyes to the brain.
Treatment typically includes vision therapy, eye glasses and contact lenses or a patch.
Surgery alone cannot treat amblyopia.
Astigmatism
Astigmatism is an irregular curvature of the front surface of the eye that results in blurred or distorted vision at all distances.
It is a common refractive error, just like nearsightedness and farsightedness.
It is usually a condition from birth that progresses over time.
Eye glasses, contact lenses and refractive surgery are all effective treatments for astigmatism.
Cataracts
Cataracts are a clouding of the eye’s crystalline lens that usually develops slowly over time.
In the case of post-traumatic or medication induced cataracts, they can also occur very quickly.
It is the leading cause of poor vision in adults.
Symptoms
Dimmed or blurred vision
Double vision
Halos or glare around lights
Dull colours
Sensation of a film over the eyes
Difficulty driving or reading
Frequent changing or cleaning of glasses
Treatment
If a cataract grows larger or denser, it can be surgically removed.
It is a safe procedure with a near 100% success rate.
Following surgery, it is normal to require a change in spectacle correction.
Prevention
Wearing UV protection when outdoors is very helpful.
There is also some evidence to suggest that a diet high in beta carotene (vitamin A), selenium and vitamins C and E have preventative benefits.
Avoiding cigarette smoke, air pollution and alcohol consumption may also help.
Diabetic Retinopathy
Diabetic retinopathy, as the name suggests, is associated with diabetes.
It is best described as damage to the retina that occurs because of defects in or leakage from the fine blood vessels.
The vast majority of those with early diabetic retinopathy are unaware of it.
In advanced cases, it can result in vision blurriness and distortion.
Diabetic patients should ensure they see their Optometrist regularly, scheduling annual eye exams.
Floaters and Flashes
Floaters are tiny flecks or threads, which seem to float in front of your eyes.
They are experienced by most people.
They are often caused by particles of protein trapped in the fluid inside the eye or by the deterioration of the fluid due to advancing age.
Occasionally they are a result of certain eye diseases or injuries or they may signal the development of more serious conditions such as retinal detachment.
They are usually harmless, but those experiencing a sudden change or increase in “spots or floaters” or flashes of light should consult their Optometrist immediately.
Glaucoma
Glaucoma is a condition in which elevated pressure in the eye damages the optic nerve, causing peripheral and total blindness.
It is widely noted as the second-leading cause of blindness in the United States.
Symptoms
There may be no early warnings, so optometric exams are crucial.
Otherwise, pain, blurred vision and the appearance of coloured rings around lights are leading indicators.
Treatment
Once diagnosed, glaucoma treatments are highly effective.
Prescription eye drops, oral medications, laser treatment or even surgery may be involved.
If untreated, glaucoma can cause blindness, and there are no cures.
Prevention
Because there may be few symptoms, and vision lost to glaucoma cannot be restored (the condition can only be halted), frequent monitoring for glaucoma is essential.
The risk of glaucoma increases dramatically after age 35 and is often hereditary.
Hyperopia (far-sightedness)
Hyperopia or farsightedness is a common refractive error.
Approximately 25% of the general population may be affected.
Farsighted individuals see better in the distance than up close because the eye does not effectively focus light.
Farsightedness is very common among elementary school-age children and a frequent cause of reading and learning difficulties.
Refractive errors such as hyperopia are commonly corrected by eyeglasses, contact lenses or refractive surgery.
Macular Degeneration
Macular degeneration is a condition in which the macula (the part of the retina responsible for sharp reading vision) fails to function efficiently.
It is a common cause of impaired reading or detailed vision – the leading cause of blindness worldwide, in fact.
Macular degeneration is generally age-related.
Symptoms
Initial signs include:
Blurred reading vision
A weakening of colour vision,
Distortion or loss of central vision (eg. a dark spot in the middle of your field of vision)
Distortion of vertical lines
Treatment
Although there is no cure, ocular vitamins, laser treatment or more commonly ocular injections can be effective in slowing the disease’s progression.
As usual, early detection is key.
Prevention
Lifelong UV protection is very important.
General nutrition is also believed to play a significant preventative role.
Zinc may be especially helpful in this regard, particularly for zinc-deficient people like seniors.
There is also some evidence to suggest that a diet high in beta carotene (vitamin A) and vitamins C and E can protect the macula.
However, an over abundance of any vitamin may affect your body’s ability to absorb important nutrients.
This is a matter of some debate among health care professionals.
Myopia (near-sightedness)
Myopia or nearsightedness is a common refractive error.
Approximately 25% of the general population may be affected.
Myopic individuals see better up close than in the distance.
This is because the eye improperly focuses too much light, causing blurred vision in the distance.
Refractive errors are commonly corrected by eyeglasses, contact lenses or refractive surgery.
Presbyopia
Presbyopia is an inevitable condition in which the ability to focus on close objects decreases over time.
Since it is a natural effect of aging, it is extremely commonplace.
Symptoms
Headaches
Blurred near vision
Tearing
Stinging
Need for more light
People with presbyopia often hold reading material at arm’s length
Treatment
Reading glasses (typically bifocals) or special contact lenses are useful treatments, although the period of adjustment can vary widely.
All told, there is a wide range of corrective options to review with your Optometrist.
Prevention
There is no recognized prevention available, although focusing difficulties can be relieved with corrective lenses.
Further Questions
For such a common condition, there are many misconceptions about presbyopia.
For example, it does not affect a person’s lifestyle, but presbyopia can require frequent prescription changes after age 40.
Refractive Laser Surgery
LASIK
Used to correct myopia, hyperopia and astigmatism
A protective flap is created to access the inner corneal tissue
Next, the inner layers of your cornea receive computer-controlled pulses of cool laser light
During this part of the procedure, an eye-tracking device tracks your eye movements to ensure precise correction.
Following the re-shaping of the tissue, the LASIK surgeon carefully repositions and aligns the flap to its original position.
Protective shields are placed over your eye to prevent accidental rubbing as the flap heals naturally and securely over the next several hours.
PRK
Used to correct myopia, hyperopia and astigmatism
The only difference between LASIK and PRK is that in PRK a flap is not produced.
Instead the outer layer tissue is removed.
After the cornea is reshaped by the laser, a bandage contact lens is placed on the eye to help promote healing.
Refractive Lens Exchange (RLE)
Used for people who have presbyopia in addition to hyperopia and astigmatism
Refractive lens exchange replaces your eye’s clear natural lens with an artificial intraocular lens (IOL) to correct your refractive problem.
For more in-depth information regarding these surgical techniques visit TLC Vision Waterloo.
Retinal Detachment
Retinal detachment is the separation of the retina from the pigment epithelium.
It is often caused by holes or tears in the retina, by a tumor or by fluid pressure in the eye.
Retinal detachment occurs among the elderly or sometimes following head or eye injuries.
There is also a higher rate of incidence among the extremely myopic.
In some cases it can be surgically treated.
Apart from sudden loss of vision, other (early) symptoms may include light flashes or an unusual number of floaters.
Strabismus (turned eyes)
Strabismus or “turned eyes” is a misalignment of the eyes.
One or both eyes may turn in (esotropia), out (exotropia), up (hypertropia) or down (hypotropia).
Treatment may include the use of eye glasses, contact lenses, prisms and/or vision therapy.
In extreme cases, surgery may be required.
Styes
A stye is a visible infection that appears at the edge of the eyelid.
Its appearance can vary somewhat, but it is harmless to your vision.
Symptoms include a noticeable swelling, some discomfort and tenderness in the affected area.
Most styes heal without treatment, although the application of a hot compress can help.
Unlike a pimple, however, styes cannot be manually ruptured and drained.
Antibiotic ointments are available for recurring cases.
For additional information, please use the links below to trusted resources that offer an extensive library of vision and eye health conditions, symptoms and more.
Eye Health Library
The Ontario Association of Optometrists Eye Health Library offers an extensive series of resources on many common eye conditions and questions.
All About Vision
This site is filled with useful information about all things related to vision and the visual system including eye disease, contacts, new technologies, etc.
*All information is provided for education and information, and is no substitute for the advice of your optometrist. This information is provided courtesy of the British Columbia Association of Optometrists (BCAO). The BCAO assumes no responsibility or liability arising from any errors or omissions or from the use of any information contained herein.