What You Need to Know
Impact of Various Conditions on Vision
The following images show how various conditions affect what a person can see.
||Age-Related Macular Degeneration
Age-Related Macular Degeneration (ARMD)
- ARMD is the leading cause of vision loss in Canada.
- In ARMD, the central area of the retina (macula) degenerates causing central vision loss. There are two forms of ARMD:
- the dry form – accounts for 80-90% of cases, and
- the wet form – less common but causes more severe and sudden sight loss.
- Symptoms of ARMD include loss of central vision, visual distortion, and loss of colour discrimination.
- Causes are not well understood. Risk factors of ARMD include genetics, light skin or eye colour, sun exposure, farsightedness, smoking, hypertension, and poor diet.
- The cause and cure for AMD are unknown. However treatments are available in a small percentage of cases.
- For advanced dry ARMD, oral vitamins that contain vitamin E, C, and zinc. Treatment of wet ARMD includes thermal laser therapy, photodynamic laser therapy, and the injection of drugs directly into the eye to reduce new blood vessel formation.
- Cataracts are a clouding of the lens of the eye. The lense becomes as cloudy as a frosted window. This clouding reduces the amount of light passing through the lens and focus on the back of the eye (retina).
- Symptoms of cataracts include sensitivity to glare, trouble distinguising colour, , hazy/cloudy vision, streaking, halos, double vision, and decreased night and distant vision.
- Risk factors for cataracts include age, trauma, certain drugs (steroids), light (ultraviolet B) exposure, smoking, diabetes, alcohol use, and a diet deficient in anti-oxidants.
- When cataracts become so severe that they affect activities of daily living, surgery is required. An operation removes the affected lens and replaces it with an artificial lens.
Diabetic Retinopathy (DR)
- DR is a disease in which changes occur in the tiny blood vessels that nourish the retina.
- Diabetic retinopathy is a complication of advanced diabetes.
- DR often has no early symptoms. A person may see specks of blood, experience blurred vision, or near vision distortion (difficulty reading)
- Not everyone with diabetes develops retinopathy, which is why dietary control (low blood glucose) and exercise are so important.
- In early stages of retinal bleeding, laser treatment of localized areas of leakage can stabilize vision. If bleeding is severe,a vitrectomy may be necessary, where blood and gel are removed from the centre of the eye and replaced with a salt solution.
- Glaucoma is a disease that causes damage to the optic nerve, usually resulting from a build-up of fluid pressure inside the eye, causing gradual loss of peripheral, or side, vision.
- Glaucoma can have few symptoms until the disease is advanced. Some warning signs include subtle loss of contrast, difficulty driving at night and loss of peripheral vision (late-stage glaucoma)
- Risk factors include age, increased fluid pressure within the eye, family history of glaucoma, being Afro-American, near-sightedness, use of cortisone (steroid) drops, and systemic diseases such as diabetes and hypertension.
- Medical treatment includes eye drops to increase the drainage of fluid or to decrease the production of fluid in the eye. Surgery is needed if the eye pressure needs to be reduced urgently.
The Canadian Association of Optometrists recommends
- Healthy adults who do not notice anything wrong with their eyes should see an eye doctor according to this schedule:
- Age 40-64 : every 2 years
- Over age 65: annually.
- An eye exam at age 40 is recommended in order to screen for eye diseases and to obtain a baseline against which vision can be later compared.
When to Seek Medical Attention
You should seek medical attention immediately in the following circumstances:
- loss of vision or decreased vision in one or both eyes
- changes in vision such as sudden spots, flashes of light, jagged lines of light, wavy or watery vision, blurry faces, distortions or wavy lines, haloes around lights, double vision
- changes in the field of vision such as shadows, curtain-like loss of vision, black spots or blurriness in central or peripheral (side) vision
- changes in colour vision
- painful eye
- redness, itching, burning, or discharge from the eye
- sudden changes of the eyelid
Tips for Preventing Injuries
Older people with vision loss are prone to falls and injuries. Here are some things that can help with prevention:
- eliminate clutter
- improve lighting and avoid glare
- outline stair edges with coloured tape
- wear glasses and use low vision aids
- use greater contrast between objects and backgrounds
- keep the home pattern-free
- install a night light between bedroom and bathroom
- Encourage open and honest communication, and assure your loved one that s/he is not a nuisance.
- Using one’s remaining vision will not cause further deterioration of an eye condition; it will train the brain to interpret images more readily.
- One of your main objectives is to help maintain the independence and dignity of your loved one.
- The best question to ask yourself is, “What can I do to help?
Canadian National Institute for the Blind
- Main Website: The CNIB is a national voluntary agency providing services to individuals across Canada to whom loss of vision is a central problem in personal and social adjustment.
- Living with Vision Loss: This document outlines understanding and adjusting to vision loss and provides great resources.
- How to Spot Signs of Vision Loss in Your Aging Parents: it is important to recognize the tell-tale signs of vision loss so that you can take preventive steps to help your parents.
- Helping Your Parent Make the Most of an Eye Appointment: This article provides suggestions to help you and your parent prepare for eye tests and appointments and make better use of your time with the doctor.
- You and Your Vision Health: Yes! Something More Can Be Done!: This online book is provided in PDF format. It includes more detailed, but easy-to-read, information about age-related vision loss and strategies for staying independent through vision support services.
- Eye Conditions: Combining simple diagrams and easy-to-understand facts, this section is an excellent resource for anyone wanting to understand more about eye conditions. The left-side menu lets users select specific eye conditions.
- Vision Problems and Your Age: This slide show explores common vision problems and more-serious eye disorders in older adults. It also discusses ways to protect your eyes and prevent vision problems.
Information Service of the Canadian Ophthalmological Society
- Eye Conditions, Disorders and Treatments provides links to patient information pamphlets.
- It's Your Health: Seniors and Aging – Vision Care: Health Canada provides this overview of conditions and steps that people can take to preserve their eyesight and remain independent.
National Institutes of Health
- This is the main information page for 'Eyes and Vision', which contains an extensive and comprehensive list of links to relevant resources.