Vision disorders can be successfully treated in childhood if diagnosed on time.
Low vision, amblyopia or, often called "lazy eye" is a vision development disorder in which the eye fails to achieve normal visual acuity, even with prescription eyeglasses, contact lenses, or laser surgery.
If low vision is not seen or treated in time, the consequences remain for a lifetime. The most sensitive period for the its development is the earliest childhood, while the visual functions are most intensively developed. Often, it only affects one eye. In some cases, visual acuity may be reduced on both eyes. What is actually happening?
It is said that we are looking with the eye but seeing with the brain. Causes of visual impairment or improper vision development can be different. But regardless of the cause, the thing they have in common is that child’s brain takes information coming from the healthy eye and ignores the ones from misaligned eye, resulting in lagging in development of the unused eye.
What causes low vision?
Strabismus (tropia) is the most common cause of low vision. Since one or both eyes are not aligned in the straightforward position and / or there is a problem with the eye mobility, the brain cannot unify two images into a single 3D so it neglects to receive information from the weak eye and receives more and more information from a healthy eye.
The weakness can be caused by refractive errors (near-sightedness, farsightedness, astigmatism). The brain relies on an eye that has a lower refractive error, suppressing the eye with a weaker image causing amblyopia on the other eye due to imbalance. This type of amblyopia is called refractive amblyopia.
Low vision can also be caused by something that prevents light entering the child's eye, such as congenital cataract with which the light entering the background of the eye is reduced due to the blur of the child's natural lens. If the cataract is present on only one eye, the brain retakes the image from a healthy eye and causes a low vision to the eye with cataract.
Low vision treatment
All vision disorders can be treated in childhood if they are diagnosed on time. Visual functions are being developed up to the age of eight. If the cause of low vision is corrected in a timely manner, the chances of proper vision development and the reduction or complete healing of are significantly increased.
Treatment is performed depending on the cause. If the cause is cataract, the removal should be done as soon as possible. If it’s caused by strabismus, it can be corrected with an operation of strabismus by which the eyes are placed in a normal position and normal mobility is established. And in this case, as well as in the case of low vision caused by dioptre and / or astigmatism, it is important to follow the doctor's instructions on eye patch covering (occlusion) of the dominant eye. That time may range from one to six hours a day.
Unlike the usual opinion and sometimes the practice of bonding the patches on the glasses, it is much more efficient to carry the patch over the eye, as it also excludes the use of peripheral vision. Parents often complain that children refuse to wear a patch, but good education and motivation can achieve excellent results. It is understandable that the resistance will be greater if the vision of the "forged" eye is considerably weaker than the one that the child's brain uses more. But with time the difference becomes smaller. One of the reasons to deprive a child of co-operation is to enable proximity (gameplay, reading, drawing) during closure, which in these circumstances contributes to the vision development of "lazy eye”.
When to check the vision?
It is important to know that a child is never too small for ophthalmology examination. Specialist examinations are customized for the child's age. Since the perceived low vision can be corrected in more than 90% of the cases and only up to the age of 8 years, mandatory ophthalmological examinations for children up to 4 years have been introduced 2 years ago. The frequency of people with low vision in Europe is 2-5%, while in Croatia this percentage is slightly higher. That is why the aim of the National Amblyopia Day, which we mark on September 12, is to point to this public health problem.
doc. dr. sc. Ivana Mravičić, ophthalmologist, subspecialist of children's ophthalmology and strabismus
If low vision is not seen or treated in time, the consequences remain for a lifetime. The most sensitive period for the its development is the earliest childhood, while the visual functions are most intensively developed. Often, it only affects one eye. In some cases, visual acuity may be reduced on both eyes. What is actually happening?
It is said that we are looking with the eye but seeing with the brain. Causes of visual impairment or improper vision development can be different. But regardless of the cause, the thing they have in common is that child’s brain takes information coming from the healthy eye and ignores the ones from misaligned eye, resulting in lagging in development of the unused eye.
What causes low vision?
Strabismus (tropia) is the most common cause of low vision. Since one or both eyes are not aligned in the straightforward position and / or there is a problem with the eye mobility, the brain cannot unify two images into a single 3D so it neglects to receive information from the weak eye and receives more and more information from a healthy eye.
The weakness can be caused by refractive errors (near-sightedness, farsightedness, astigmatism). The brain relies on an eye that has a lower refractive error, suppressing the eye with a weaker image causing amblyopia on the other eye due to imbalance. This type of amblyopia is called refractive amblyopia.
Low vision can also be caused by something that prevents light entering the child's eye, such as congenital cataract with which the light entering the background of the eye is reduced due to the blur of the child's natural lens. If the cataract is present on only one eye, the brain retakes the image from a healthy eye and causes a low vision to the eye with cataract.
Low vision treatment
All vision disorders can be treated in childhood if they are diagnosed on time. Visual functions are being developed up to the age of eight. If the cause of low vision is corrected in a timely manner, the chances of proper vision development and the reduction or complete healing of are significantly increased.
Treatment is performed depending on the cause. If the cause is cataract, the removal should be done as soon as possible. If it’s caused by strabismus, it can be corrected with an operation of strabismus by which the eyes are placed in a normal position and normal mobility is established. And in this case, as well as in the case of low vision caused by dioptre and / or astigmatism, it is important to follow the doctor's instructions on eye patch covering (occlusion) of the dominant eye. That time may range from one to six hours a day.
Unlike the usual opinion and sometimes the practice of bonding the patches on the glasses, it is much more efficient to carry the patch over the eye, as it also excludes the use of peripheral vision. Parents often complain that children refuse to wear a patch, but good education and motivation can achieve excellent results. It is understandable that the resistance will be greater if the vision of the "forged" eye is considerably weaker than the one that the child's brain uses more. But with time the difference becomes smaller. One of the reasons to deprive a child of co-operation is to enable proximity (gameplay, reading, drawing) during closure, which in these circumstances contributes to the vision development of "lazy eye”.
When to check the vision?
It is important to know that a child is never too small for ophthalmology examination. Specialist examinations are customized for the child's age. Since the perceived low vision can be corrected in more than 90% of the cases and only up to the age of 8 years, mandatory ophthalmological examinations for children up to 4 years have been introduced 2 years ago. The frequency of people with low vision in Europe is 2-5%, while in Croatia this percentage is slightly higher. That is why the aim of the National Amblyopia Day, which we mark on September 12, is to point to this public health problem.
doc. dr. sc. Ivana Mravičić, ophthalmologist, subspecialist of children's ophthalmology and strabismus