Lazy Eye – Symptoms and Causes
Overview
Lazy eye happens when one eye has weaker vision than the other. This condition usually starts early in life, from birth until about age 7. The weaker eye may point inward or outward.
Lazy eyes are the main reason children have vision problems. It rarely affects both eyes at once. When caught early, treatment works well for most children.
There are various effective treatment options available for addressing lazy eye. Children often need eyeglasses or contact lenses to help the weaker eye.
Patch therapy is another common approach. This involves covering the stronger eye for parts of the day to force the brain to use the weaker eye.
Early treatment is important to prevent lasting vision problems. Regular eye check-ups help find this condition before it causes major issues.
Signs of Lazy Eye
People with a lazy eye may show several visible symptoms:
- Eye wandering inward or outward
- Poor coordination between both eyes
- Reduced depth perception
- Squinting or closing one eye
- Tilting the head to see better
Some people show no obvious signs, and the condition is only found during an eye exam.
When to See a Doctor
If you notice your child’s eye wandering after the first few weeks of life, contact their doctor. This is particularly important if your family has a history of:
- Crossed eyes
- Childhood cataracts
- Other eye conditions
It’s recommended that all children have a complete eye exam between ages 3 and 5, even without symptoms.
Causes
Lazy eye happens when early vision problems change how the eye and brain connect. The brain gets fewer signals from one eye, causing it to favor the stronger eye and ignore the weaker one.
Several factors can trigger this condition in children:
Eye Muscle Problems
When eye muscles don’t work together properly, they can cause the eyes to cross inward or turn outward. This muscle imbalance prevents both eyes from focusing together and is the most common reason for lazy eye development.
Vision Sharpness Differences
When one eye sees much more clearly than the other, lazy eye can develop. This happens with farsightedness, nearsightedness, and astigmatism (uneven eye surface).
Doctors usually prescribe glasses or contacts to fix these vision differences. Some children have both muscle imbalance and vision sharpness issues contributing to their lazy eye.
Vision Blockage
Something blocking clear vision in one eye, like a cataract (cloudy lens), can lead to lazy eye. This type often needs quick treatment in babies to prevent permanent vision loss and can be the most severe form.
Any condition that makes a child’s vision blurry or causes eye misalignment can result in lazy eye. When one eye doesn’t see clearly, the brain gradually reduces its connection with that eye, making the condition worse over time.
Risk Factors
Several factors may increase a person’s chance of developing lazy eye:
- Being born too early
- Low birth weight
- Having family members with lazy eye
- Having developmental disabilities
Possible Problems Without Treatment
If a lazy eye is left untreated, it can lead to lasting vision problems. The brain might start to ignore signals from the weaker eye, making the vision loss permanent.
Children with untreated lazy eye may face limited depth perception. They may also experience reading difficulties and problems with certain sports and activities. In addition, they may have possible vision loss in the affected eye.
Most doctors recommend addressing lazy eye before age 7, when visual development is most active. However, some research shows improvements can happen in older children and adults too.
