blind low vision Flashcards
what is blind / low vision
What is blind or low vision?
- Low Vision: the loss of sight that is not correctable with regular glasses or contacts. In this type of vision loss there is still some sight, but visual acuity is 20/70 or poorer
- Legal Blindness: visual acuity no better than 20/200 with conventional correction and/or a restricted field of vision less than 20 degrees wide
- Complete Blindness: unable to see or discern any images
diagnosis
- Diagnosis is determined by an optometrist, paediatrician or ophthalmologist
- This process begins with examining family history of visual impairment, health integrity and function of the eye
- Tests that diagnose visual acuity and visual impairment come in many forms.
- Some of these types include the Snellen test, visual field test, tonometry test and ocular motility assessment
the snellen test
- The Snellen test is the most common
- A chart with differing sizes of random letters is held 6 meters away from the patient
- The patient is asked to read the letters with each eye separately and both together
- Then given a low vision classification o B1:Total absence of perception of light in both eyes, or some perception of the light but with the inability to recognize the form of a hand at any distance and in any direction
o B2:From the ability to recognize the form of a hand to a visual acuity of 20/600 and/or a visual field of less than five degrees
o B3:From a visual acuity of above 20/600 to a visual acuity of 20/200 and/or a visual field or more than 5 degrees to less than 20 degrees
congenital causes
- Retinitis Pigmentosa: passed on through genes
- Cortical visual impairment: neurological disorder, which results in unique visual responses, disruption between perception of images
- Albinism: Hereditary condition resulting in lack of pigment in eyes, skin and hair. This can lead to sensitivity to bright light and glare, and other vision problems
- Retinitis of prematurity: Results from premature birth, when growth of blood vessels in the retina stops and an increased risk of retinal detachment occurs
- Optic Nerve Hypoplasia: underdevelopment of the optic nerve during pregnancy
- Others result from a disease or deficiency during pregnancy
acquired causes
- Glaucoma: damage to optic nerve which increases pressure in the eye
- Age related macular degeneration: affects the retina, causes blurred vision.
○ Leading cause of low vision in individuals older than 60
○ Nearly half of all low vision cases in adults - Cataracts: clouding of eyes which interferes with the amount of light entering the retina
○ Caused by aging, long exposure to sunlight, injury - Retinal detachment: retina detaches from the central layer
- Infection of the cornea or retina
- Cancer of the eye
- Traumatic injury
- Inability to obtain glasses
- Poor nutrition
- Correlation between diabetes, stoke, MS
symptoms
- Individuals who are blind or have low vision have the common difficulty of seeing
- Discomfort in eyes
- Pain or discharge in the eyes, depending on the cause
- Eye redness
- Nausea
- Sensitivity to light
- Difficulty with colour differentiation
- Vision impairment ranges from mild to severe
- A visual diagnosis will not affect each person in the same way
- Most common types of low vision
o Loss of central vision: blind spot in the centre of vision
o Loss of peripheral vision: inability to see above, below or peripheral but central vision is clear, tunnel vision
o Night blindness: Poor vision in low lit areas or outdoors at night - Total blindness: is the complete lack of light and form perception
treatment
Treatment of blindness depends on the cause
- Some cases can be treated and cured if caught in time; these include cataract and gluacoma
- Some common treatments include:
○ Surgery
○ Inflammatory or infection medication
○ Providing glasses
○ Dietary changes
- Meanwhile, other cases do not have a cure; such as age-related macular degeneration
implications
● Multiple studies show that blindness, deteriorating sight, and other visual impairments are highly associated to various negative health effects and an overall decrease in quality of life.
● Blindness, especially acquired blindness, not only affects the person, but also their social circle and immediate peers.
● Blindness and Low-Vision affects most, if not all, dimensions of a person’s health
○ Physical
○ Emotional/Affective
○ Mental/Cognitive
○ Social/Interpersonal
○ Occupational/Financial
dimensions of health
Physical
● People with blindness and visual impairments are less
likely to be active.
Emotional
● Develop low self-esteem and negative self thoughts.
Acquired is often followed by depression.
Mental
● Information is harder to access. Despite recent
developments, some information is still out of reach.
Social
● Lack of self confidence and motivation. Not quite
equal opportunities to socialize.
Occupational
● Lower rates of employment compared to the rest of
the population.
accessibility
been seen in accessibility in Canada. Daily Living: ● Auditory cues in crosswalks. ● Textured Paths ● Website/Computer Narrators ● Voice Commands Leisure and Entertainment ● Auditory descriptions and narrators for museums, theaters, cinemas, sports, computers, etc. ● Braille in every visible sign and places required: ● Bathrooms, Elevators, Floors, Rooms, and Restaurant menus in braille ● Education of the hiring managers to consider people with blindness and low-vision.
accessibility in PA
Low rates of physical activity among people who
suffers from loss of vision and low-vision are due to the lack of programs and lack of physical activity also contributes to depression and perceived loneliness.
Physical Activity
● Create more recreational programs and
leagues for people with blindness.
● Educate the educators to adapt their
classes for inclusivity
● More sports and physical activity can also
lead to more opportunities to socialize
PA implications
- Only 1% of those living with a visual impairment participate in sport (Canadian Blind Sports)
- This is due to many factors including inexperience, lack of opportunities and awareness, inadequate access and a lack of support from teachers and caregivers
- Early involvement in physical activity is critical to developing an active healthy lifestyle
motor development
- Children with low vision / blindness have been known to demonstrate less developed motor skills when compared to their sighted peers
- To minimize the delay of motor development, students must be provided the opportunity to learn fundamental movement skills as soon as possible
- Students must be provided a safe environment where they can feel confident to learn a new skill
balance
- One of the main problems facing those with low vision is poor balance
- Balance is strongly affected by not having a visual reference point to focus on
- Some activities to help improve this include dance, yoga and guided gymnastics, etc.
fear
- Children with congenital conditions are often used to moving freely in new environments, but those who have acquired low vision tend to be apprehensive when in a new environment and may choose not to participate in many activities
- Ways to minimize this include:
- Pre-teaching: spend time with the student before class to introduce them to the environment and go over the new skill so they have an understanding of where everything will be and what is expected of them
- Parents: Children often inherit their fear of PA from their parents who are too afraid to let their child participate. Work with parents to help reduce their concerns; provide status updates, send photos of their child participating, provide ideas for PA outside of school
