Refractive Errors

Dr. Burke is one of Cincinnati’s most trusted resources concerning visual development in children.

What does a baby see?

A baby is born with the eyes and the brain having the wiring diagram needed for vision. However, these circuits must be turned on and these systems used continuously to stimulate and fully develop the brain’s visual systems.

This means newborn infants are born with a potential to see and, as they use their eyes during the first years of life, the visual functions continually and significantly improve.

The maximum visual system potential is reached around 2 years of age but the brain’s visual development does not become fully mature and stable until around the age of 8.

What must happen for a baby see?

The baby’s visual system is dynamic, constantly changing, and adapting through nature’s pre-programmed developmental cycle and through the use of the eyes that stimulate the brain’s development.

The baby’s ability to understand what is seen and being able to make appropriate responsive actions based upon that information is a learned behavior. That means that the sensory experiences from the external world influence the way the brain wires itself after birth.
These visually driven experiences stimulate the development of the different areas of the brain used for facial and object recognition, perception of movement, color vision, and depth or 3-D awareness.

Visual experiences are crucial for the child’s vision to develop normally. The infant’s visual system develops in a “use it or lose it” situation. Because visual development is so rapid during the first year, early detection of eye problems is critical so that treatment of childhood eye problems may begin as early as possible so that permanent visual impairment does not occur.

What is the typical visual developmental progression in infants?

Right after birth, the baby’s may appear to stare blankly and the eyes may appear to wander almost randomly. They typically show blinking or closing of the eyes in response to rapid increases of illumination.

During the first month or two, they may focus only on stationary objects close to their face. This is especially true when looking at your face. Although it does seem that they enjoy looking at faces, they are actually observing only gross facial details. The early visual system is more stimulated by and therefore interested in shapes, lines, and boundaries between the image targets.
In this immature visual system, the nearness of the visual stimulus allows for magnification that permits the infant’s best visual potential.

In the second and third month, they have learned to fixate well on faces and lights and then they begin to perceive larger distant objects. They also slowly develop the ability to fix and follow or track objects that are in motion.

By 3-4 months, the brain has developed enough to control of the eyes and head movements, which allows for the rapid integration of visual stimuli that permits the infant to respond so that their eyes appear well aligned and the tracking of their ocular movements are well coordinated most of the time. Also during this time, the baby’s visual attention and visual searching behavior begins which allows the infant to associate visual stimuli with a recurring event (such as a bottle “means” food).

By the time your infant is 4-6 months old, most visual systems should be functioning so that it appears that their visual interests and abilities are as good as an adult. But their vision is not as good as yours and their brain’s vision systems are not nearly fully developed. It is not until around 24 months of age that the eye’s and brain’s anatomic development reaches close to that of an adult. However, the brain’s visual circuits do not reach full maturity and stability until around the age of 8 years.

What should you do if you suspect something is wrong with your child’s eyes or their vision?

Please remember that babies develop their abilities at their own pace and without regard to time tables that parents and grandparents often set for them. Even if your baby seems behind any of these developmental milestones (listed above), the probability is the visual functions and development will ultimately be normal.

However, if by 3-4 months of age your child’s vision seems less than normal or if the eyes do not appear properly aligned, you should bring these issues to the attention of her primary care provider. If you really feel there is still a problem, even if your primary care practitioner feels it is probably normal, it is always worth getting an opinion from a pediatric ophthalmologist.

What are some of the factors that increase the risk of a vision problem in an infant?

  • Prematurity less than 32 weeks
  • Maternal history of diabetes or thyroid instability
  • Maternal use of illicit drugs and alcohol
  • Maternal exposure to or infection with herpes, toxoplasmosis, chlamydia, cytomegalic virus
  • Family history congenital cataracts
  • Family history of genetic diseases including neurofibromatosis, Marfans, optic atrophy, retinitis pigmentosa, Stickler’s
  • Family history of retinoblastoma
  • Known or suspected central nervous system problems including developmental delay, cerebral palsy, seizures, and hydrocephalus
  • Down syndrome
  • Family history of unusually high farsightedness
  • Family history of strabismus
  • Ptosis or any other cause of visual axis blockage

Dr. Burke is one of Cincinnati’s most trusted resources concerning vision screening in children.

What is vision screening?

Most vision screenings are designed to check the child’s eyesight. Vision screening is an efficient and cost effective “safety net” method to identify children with visual impairment so that a referral may be made with a pediatric ophthalmologist for further evaluation and, if necessary, proper treatment.

Where are vision screenings performed?

During most healthy checkups, your primary care practitioner performs an eye and vision screening that is appropriate for the child’s age. School vision screening should also be done yearly. Vision screenings are not intended nor should they be assumed to replace a thorough examination by a pediatric ophthalmologist.

What parents need to know about visual acuity testing?

Subjective visual acuity testing means asking a child to tell you what they see. To obtain measurements that are accurate requires a cooperative individual. The child must give their best effort and the examiner must be sure they are testing each eye separately and making sure the child does not peek with the other eye. Without these requirements, there will be many “false positive” results. “False positive” refers to the measurements not accurately representing the child’s maximum potential. With the proper amount of encouragement and patience, most children 3 years and older are able to cooperate.

What should you do if your child he fails a vision screening?

About 4% of children have a serious eye problem and up to another 10% have decreased vision due only to a refractive error that could be corrected by glasses. Therefore, if a child fails a vision screening or if the parents or primary care practitioner suspects there may be another problem with the eyes, it is reasonable and appropriate for your child to have an eye examination with a pediatric ophthalmologist.

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Dr. Burke is one of Cincinnati’s most trusted resources concerning refractive errors in children’s eyes.

Why are children’s visual needs different than adults?

A child’s visual system is in the developing stages till 2 to 3 years old and remains immature (and therefore remains susceptible to amblyopic concerns and fortunately responsive to amblyopic therapies) until around 8 years of age.

Why are glasses prescribed for children?

Glasses are prescribed for children to 1) improve vision, 2) prevent and treat amblyopia (“lazy eye”), and 3) to help straighten eyes that have special types of eye muscle problems. Children with focusing problems such as myopia, hyperopia, and astigmatism may also need corrective lenses.

What are the three types of refractive errors?

Myopia, hyperopia, and astigmatism are refractive errors. Most eyes have similar refractive errors. However, when there is a significant difference in the refractive error between the eyes, this asymmetry is called anisometropia. Anisometropia is one of the main causes of amblyopia in children.

What is myopia?

Myopia, or nearsightedness, is inherited and is often discovered in children when they are 8-12 years old. A myopic eye is longer than normal, causing light rays to focus in front of the retina. This causes close objects to look clear, but distant objects appear blurred.

What is hyperopia?

When light entering the eye is focused behind the retina, we call this hyperopia or farsightedness. A hyperopic eye is shorter than normal. Most young children are normally a little farsighted but have no problems seeing objects up close or at a distance. Hyperopia needs to be corrected in children if it causes decreased vision or were associated with crossed-eyes.

What is astigmatism?

Astigmatism occurs when light rays entering the eye and are focused at different places on the retina. In astigmatism, the cornea may be said to be warped or slightly distorted. Astigmatism blurs vision for both near and far objects.

Are refractive errors considered a disease?

Basic refractive errors are usually thought of as irregularities of the eye and not as diseases. Glasses do not weaken the eyes nor will they cure a refractive error. Glasses are simply an external optical aid that neutralizes or clears the vision. However, there are special situations where refractive errors do play a part in children’s eye problems. In children with amblyopia, glasses are used to help teach the brain to see more clearly. In children with accommodative esotropia, glasses relax focusing effort, which helps the eyes to be straighter.

What happens to refractive errors with growth?

Refractive errors change as the eyes grow. Refractive errors are genetically controlled so similar refractive errors typically run in families. Infants and young children are commonly mildly farsighted. During the pre-pubertal years, typically between 8 and 12 years old, up to 40% of children lose their childhood farsightedness and become nearsighted. This growth related change continues as long as development and maturation continue, typically until 16-18 years old in females and into the early 20s for males. Although there are many areas of research attempting to slow the progression of myopia, there is no consensus on any reliable therapy at this time.

Additional Information:

Dr. Burke is one of Cincinnati’s most trusted resources concerning glasses needs in children.

Eyeglass frames come in all shapes and sizes, so choosing one that will fit the child’s needs is important. Whenever possible, purchase the glasses from an optician who is experienced working with children. Let them recommend the most suitable frame for the child’s facial features, age, prescription, and activities. Ask about warranties for your child’s eyeglasses and seriously consider purchasing one for at least one year from the date of purchase.

Most lenses in the eyeglass frame are made of a plastic polycarbonate material. Polycarbonate lenses are very lightweight yet are especially strong and shatterproof offering the child significant protection. Children who have good vision in only one I should wear polycarbonate glasses for protection at all times even if they do not otherwise need glasses.

Cable temples (soft plastic material wrapping around the ears for added support) are recommended for infants and particularly active toddlers. Flexible or spring hinge allow for some outward bending of the temples and are particularly useful to prevent breakage.

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Dr. Burke is one of Cincinnati’s most trusted resources concerning eyeglasses for infants & children.

Why are glasses prescribed for children?

Glasses are usually prescribed for children to improve vision or to prevent and treat amblyopia (“lazy eye”) or eye muscle problems. Children with focusing problems such as myopia, hyperopia, and astigmatism may also need corrective lenses.

How are glasses prescribed?

The focusing power of a baby’s eyes can be tested even before he or she is able to speak. After dilating a baby’s pupil, the ophthalmologist uses an instrument called a retinoscope to determine the focusing power of the eye. Children who talk but do not yet know their letters or numbers can be asked to identify pictures of common objects to help determine the lens power they need.

How do you choose a suitable frame with a proper fit?

Frames come in all shapes and sizes, so choosing one that will fit the child’s needs is important. Ask the optician to recommend the most suitable frame style for the child’s facial features, age, prescription, and activities. Ask about the quality and expected lifetime of the frame and the frame guarantee, if there is one.

What types of lenses are the best?

Lenses made of impact resistant plastic are preferable. Polycarbonate lenses are the most common and offer the most protection for a child. Polycarbonate is an especially strong, shatterproof, and lightweight plastic. Prescription sunglasses and transition lenses (become darker in sunlight) may be purchased if your child is sensitive to light.

How do I keep the glasses on my child?

Don’t make a big fuss about the glasses. If your child is old enough, let him or her help pick out the frame. Be sure to follow your optician’s advice about the proper frame size and fit because these are often more important than the appearance of the frame. Be positive about the glasses and your child’s appearance in them.

Don’t get into a tug-of-war with your infant. Try to distract him or her after you put the glasses on. If your child removes them, put them back on. If it happens again, set the glasses aside for a while and try again later. If your child continues to remove the glasses, call Dr. Burke for further instruction and directions.

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Glasses For Children

Fitting Glasses For Children