The American Academy of Ophthalmology and the American Academy of Pediatrics recommend that the first vision screening be conducted for a newborn prior to being discharged from the hospital. Visual function will be monitored by your child’s pediatrician during well-child exams (usually at two, four and six months of age). If there are any signs of an eye condition, your child may be referred to an eye care provider. Beginning at three years of age (and yearly after five years of age), amblyopia (poor vision in an otherwise normal appearing eye), refractive and alignment screenings should take place. If you notice any signs of decreased vision or misalignment of the eye, please contact your eye care provider for a complete eye examination.
Visual Acuity Test
A Visual Acuity Test is a routine part of an eye examination performed to determine the smallest letters a patient can read on a standardized chart that is 20 feet away. You will be asked to remove your contact lenses or glasses and gently cover one eye with the palm of your hand while reading aloud the smallest line of letters you can read on the chart. The test is performed on each eye, one at a time.
Your visual acuity will be expressed in a fraction. The top number represents the distance you stand from the chart, while the bottom number represents the distance at which a person with normal eyesight could read the same line you read correctly. For example, normal vision is considered 20/20. If your visual acuity is 20/40, then this indicates that the line that you correctly read at 20 feet can be read by a person with normal vision from 40 feet away.
Refraction Assessment
A refraction assessment helps your eye doctor determine the most accurate corrective lens prescription that will give you the best possible vision. You will be asked to look through a Phoroptor, a mask-like device that contains different lenses, which will help determine the best combination that will give you the sharpest vision.
Retinoscopy
A retinoscopy test will usually be performed early in the eye exam so the eye doctor can determine an approximate prescription from which to start. With the room’s lights dim, you will be asked to look through a machine and focus on a large target (usually the big “E” on the chart). Your doctor will shine a light in your eye and flip lenses on the machine. Based on the how the light reflects on your retina, the doctor will be able to calculate your refractive error.
Autorefractor Testing
An autorefractor is sometimes used by doctors to determine a patient’s prescription. A chin rest will help stabilize your head while you look at a pinpoint of light. It is used to evaluate the way your retina focuses an image. Autorefractors are commonly used in evaluating children’s’ eyes.
Strabismus (Lazy Eye)
Strabismus, also sometimes called “lazy-eyed”, “cross-eyed” or “wall-eyed,” is a condition that occurs when a person cannot align both of their eyes on a single object at the same time under normal circumstances. According to experts, it is estimated that roughly five percent of all children have some degree of strabismus. Movement of the affected eyes could either occur all the time (called “constant strabismus”) or under certain conditions like high stress or illness (called “intermittent strabismus”). Children with strabismus will occasionally experience double vision as a result of the conflicting signals from their eyes. Eventually, their brains learn to disregard one of the eyes, but this does not affect the actual condition of the eye. Early treatment is strongly advised for children with strabismus because it is not a condition that children “grow out of”. Some common treatments for strabismus include optical devices, vision and muscle therapy, and, as a last resort, surgery. For an in-depth consultation, schedule an appointment with our office as soon as possible.
Color Recognition
By age 4 years 9 months, 90% of children recognize 4 colors. If you child is delayed in recognizing his/her colors, some questions to ask are:
- Does he/she recognize pictures in books?
- Can he/she count to 5?
- Does he/she know his letters?
- Can he/she spell his name?
- Does he/she know the primary colors (red, yellow, blue)?
- Do other family members have problems with color vision, like recognizing traffic lights?
If he can do all of these other things but still does not recognize colors, there may be a problem.
Color vision defects (dyschromatopsia), often called color blindness, are a common problem. These defects may either be congenital (you are born with it) or acquired later in life. Defects can range from total color blindness, which is rare, to just having problems confusing colors, like blues and violets, red and brown, green and brown, green and gray, green and white, blue and purple, red and yellow, or red and green. Red/Green color blindness is the most common color vision defect, causing problems distinguishing reds and greens.
Plate tests, in which symbols made up of colored dots are 'hidden' inside other colored dots, are often used to test children in whom color recognition is suspected. These tests however are more difficult to use on younger children, so we may use shapes instead of letters or numbers.
In school, being color blind can cause difficulty if teachers are using colors to represent things that they are trying to teach your child and he or she can't tell the difference between the colors. Early detection will assure that you can make your child’s teacher aware of any problems that exist.