vision loss evaluation

overview

a low-vision evaluation will help you and your doctor find ways to make the best use of your remaining vision.

your doctor will ask questions to find out how your vision loss has affected your life and what changes you have already made to cope with reduced vision. talk with your doctor about your needs and goals. questions may include the following:

• what are the problem areas associated with your vision loss? how has your life changed? what activities have become harder, and which ones are the most important to you?
• can you do home-based tasks using near vision, such as reading your mail or a newspaper or managing bank accounts and paying bills? have you tried using a magnifying glass?
• what sort of lighting do you have in your home? do you use a night-light? the doctor may ask other questions about your home environment.
• can you do tasks that require distance vision, such as recognizing faces or seeing traffic signals? are you still able to drive?
• can you still travel and function in your environment? do you bump into obstacles, such as curbs, or miss steps? can you find items you want and count your money when shopping? if you are still working, does your vision loss affect how well you can do your job?

other questions may deal with your current living situation, whether you live alone, and what sort of assistance is available to you. your family members or others close to you may also be asked to provide information.

examinations for remaining visual ability

your doctor will do visual tests to find out the quality of your remaining vision, including:

• visual acuity for both near and distance vision. visual acuity tests measure the eye's focusing power and your ability to see details at near and far distances. they usually involve reading letters or looking at symbols of different sizes on an eye chart. these tests will also take into account any refractive error in your vision, such as nearsightedness or farsightedness.
• defects in both central vision and side (peripheral) vision. these tests look for flaws and blind spots (scotomas) in your visual field, which is the entire area seen when your gaze is fixed in one direction. the complete visual field is seen by both eyes at the same time, and it includes the central and peripheral visual fields.
• contrast sensitivity. these tests measure your eye's ability to distinguish objects and their surroundings based on differences in brightness or colour (contrast), rather than shape or location. the tests may also show how much light (illumination) you need to be able to distinguish objects with similar brightness or colour (low contrast). because side (peripheral) vision is less sharp than central vision, contrast may play a more important role in helping you locate and identify objects if you lose some central vision.

your doctor may also conduct vision tests for brightness acuity (which may show how sensitive you are to glare), colour perception, and how well your eyes work together to provide depth perception.

consultations with other specialists

a low-vision evaluation may also include consultations with specialists such as an occupational therapist or a social worker who can provide counselling and training on dealing with reduced vision to help you keep your quality of life as much as possible. if you are working with your primary care doctor, the consultations will also include an eye care specialist such as an ophthalmologist or optometrist. your own eye doctor may refer you to another who specializes in low-vision evaluation and rehabilitation.

to understand your home environment and your needs, a low-vision evaluation may also include home visits by your doctor or by rehabilitation specialists.

when the evaluation is complete, you and your doctor will be able to identify ways for you to make the best use of your remaining vision.