Definitions of Vision Testing
Vision Screening Test
A test that is used to make general categorizations of examinees (i.e. students). Vision screenings typically test only for distance vision. Vision screenings are performed by school nurses. In many instances volunteers also perform vision screening tests. Equipment called “vision screeners” maybe used for the testing and run by the volunteers and/or school personnel. Vision screening tests are a valuable component to vision care but should not be thought of as a comprehensive vision examination.
A vision assessment is a systematic method of obtaining evidence from a series of defined tests that is used to draw inferences about the health and function of the visual system. “See To Learn” is an example of a vision assessment available free of charge from a “See To Learn” provider for every three year old in the state of Nebraska. Vision assessments are valuable to determine a child’s possible problems with visual health and function but vision assessments do not replace comprehensive vision examination.
School Vision Evaluation
All students new to Nebraska schools are required by law to receive a vision evaluation. This evaluation consists of requirements to examine specific components of a student’s visual system: Amblyopia (lazy eye), strabismus(misalignment of the eyes), internal and external health of the eye, and visual acuity. The vision evaluation must be performed by an optometrist (OD), physician (MD), a physician assistant (PA), or an advanced practice registered nurse(APRN).
The school required vision evaluation is important to insure that all students entering Nebraska schools for the first time are prepared to learn. However, the testing and observation components are not complete enough to be considered a comprehensive vision evaluation.
A Comprehensive Vision Examination is a series of tests and observations that measure the health and function of an individual’s visual system. A comprehensive vision evaluation can only be performed by law within the scope of practice by an optometrist (OD) or ophthalmologist (MD).
Exam and Screening Comparisons
The Elements of a Comprehensive Eye Health Exam and Vision Analysis The American Optometric Association (AOA) recommends the following information be gathered and tests be performed during a comprehensive eye examination:
- Chief Complaint: assessment of the patient’s reason for getting an eye exam.
- General Physical Health History: complete health history to screen for physical conditions and medications that may affect eyesight.
- General Ocular Health History: complete eye health history including family history of eye conditions, disease, or medication.
- External and Internal Eye Health Evaluation: examination for the signs of eye disorders, including cataracts and other eye disorders.
- Current Prescription Analysis: evaluation of current lens prescription, if applicable.
- Visual Acuity: test for the eyes’ ability to see sharply and clearly at all distances.
- Refraction: test for the eyes’ ability to focus light rays properly on the retina at distances and close by.
- Tonometry: test to measure internal fluid pressure of the eye (increased pressure may be an early sign or glaucoma).
- Visual Coordination: check for external eye muscle balance and coordination.
- Accommodative Ability: test of the eyes’ ability to change focus from distance to near. An exam may also include tests for color vision and depth perception, visual fields, and other vision skills, as needed.
Most screenings assess visual acuity from 20 ft but don’t evaluate other distances, including reading distance.
Standards and criteria for ‘passing’ a screening vary
Experience and resources can vary significantly among people conducting screenings.
“Passing” a screening can give a false sense of security.
Children can peek, memorize correct answers, and otherwise compromise their answers when reading a vision chart
The Vision and Learning Connection
More than 80% of learning in the classroom is visual, and it is apparent that if a child cannot see, a child cannot read, and if a child cannot read, a child cannot learn.
Based upon national statistics, as many as 4,500 Nebraska children enter school each year with vision problems significant enough to hinder their ability to learn. Undetected vision problems often result in students being placed in the wrong treatment track (e.g. remedial reading, special education) at costs to parents and the state.
Students with a vision disorder will likely not focus on the book, whiteboard or computer or attempt to complete schoolwork and may be labeled with a behavior disorder due to their inability to “behave” in the classroom.
Many of our state’s young children are faced with overwhelming social and emotional challenges that can impact their ability to learn, but vision is one part of the equation that can most likely be controlled. Preventative measures include proper detection through a complete eye exam.
Follow this link if you’d like to learn more about the warning signs for visual issues in children.
Exam Frequency Recommendations
- 6-12 Months of Age
- 3 Years Old
- Before Kindergarten
- Yearly after that
Pediatric Vision Development
It is important to watch your baby’s development to ensure they reach their milestones.
A child’s vision is a complex combination of the brain, the eyes and the vast array of nerves that connect them. At birth, this visual system is still immature and continues to develop throughout the child’s early years.
Clear vision is an integral part of a child’s healthy development.
Healthy eyes and good vision are vital components that enable successful achievement of many important milestones. Learning “how to see” and being able to interpret visual information to understand what is going on in the environment, are both crucial factors in successfully reaching the development of the visual system.
These developmental milestones begin in the infancy stage and are dependent on the strength of the visual skills. Visual skills, such as binocular vision, accurate eye movements, and the ability to change focus to see near and distant objects, are necessary for observing, imitating, learning, playing, and more.
When does vision development begin?
Vision development begins in the womb and continues throughout childhood and adolescence.
The development of a mature visual system is especially critical within the first six years of life.
The first six years of life is considered the “vulnerable period” because it is a time when the child’s development is most vulnerable to the effects of the various threats to their eye health and vision. Any change in vision or ocular health can inhibit a child from developing the necessary visual skills, and cause developmental delays.
A parent’s role in vision development
Parents play a vital role in their child’s healthy development of vision. It is therefore important for parents to:
- Watch for signs of a vision problem
- Schedule their first eye exam at around 6 months of age
- Follow your eye doctors advice on an appropriate schedule of eye exams
- Engage in parent-play age-appropriate activities that can stimulate your child’s vision, such as swing mobiles, soft toys and playful games
- Allow children to safely explore and interact with their natural environment, such as playing in a sandbox or climbing a tree
- Provide challenging physical experiences, such as riding a tricycle and catching balls
- Increase the visual demand of play and activities, such as sports and flashcards
Vision milestones according to age
The following is a timeline of some of the key visual age-based milestones, to provide a basic guideline for parents to know what to expect throughout their child’s development.
It is important to remember that each child is unique and may reach certain milestones at different ages.
Please note, this is ONLY a guideline, and should not be used to replace the consultation of an eye care professional.
Birth to 1 month
- Blinks in response to bright light
- Uncoordinated eye movements— may appear “crossed-eyed”
- Ability to stare at an object 8-10 inches away
- Stares at light or face
- Begins to track or follow moving objects
1 to 2 months
- Clear vision only for objects 10-12 inches away
- Stares at faces and black and white images
- Follows an object up to 90 degrees
- Watches parent closely
- Begins to develop tears
2 to 3 months
- Begins to notice familiar objects up to 12 inches away
- Examines own hands
- Follows faces, objects, and light
4 to 5 months
- Begins to reach for nearby objects, such as a hanging mobile
- Recognizes objects such as a bottle or pacifier
- Looks at self in mirror
5 to 7 months
- Develops full color vision
- Ability to see images and objects from few feet away
- Turns head to view objects
- Favors certain colors
- Touches mirror image of self
7 to 12 months
- Development of independent eye movements
- Sees smaller objects
- Development of depth perception
- Crawls to reach distant objects
- Plays peek-a-boo
- Watches and follows fast moving objects
12 to 18 months (1 to 1.5 years)
- Clear distance vision
- Depth perception for objects further than 2 feet away
- Refinement of eye movements
- Recognizes images of familiar objects
- Walks to interact with interesting items
- Recognizes self in mirror
18 to 24 months (1.5 to 2 years)
- Begins to focus on objects closer than 2 feet
- Clear distance vision
- Development of fine-motor skills
- Colors with crayons— attempting to draw straight lines or circles
- Identifies body parts —mouth, eyes, and hair, etc.
24 to 36 months (2 to 3 years)
- Improvement of close vision skills: convergence and focusing
- Development of binocular vision at all distances
- Can change focus from distance to near
- Improvement of depth perception
- Uses focusing to recognize shapes and objects
36 to 48 months (preschool)
- Distance vision nearing 20/20
- Clear and single vision up to few inches from face
- Development of gross-motor coordination
- Recognizes complex visual shapes and letters
- Identifies colors
48 to 72 months (school)
- Knows letters and some words
- Recognizes orientation of letters
- Begins reading
- Possesses a matured sense of depth perception
- Clear, single and comfortable vision at all distances