Q. I've heard of the childhood eye conditions strabismus and amblyopia, but I'm not quite sure what the causes them. Is it true that they can be quite dangerous and even cause blindness
A. You are right that these eye conditions can cause blindness if left untreated. However, if detected and treated early, no lasting visual problems should result. Amblyopia (also known as "lazy eye") is when vision is weakened in one or both eyes, while strabismus is the medical term for crossed eyes. It's important to know that one condition can lead to the other. Amblyopia, for instance, usually results from untreated crossed eyes.
Don't panic if your infant's eyes appear to be crossed. It's normal for babies' eyes to be crossed in the early months of life and straighten out by the end of the first year. (This is why during each well-baby checkup the doctor shines a light into the baby's eyes to see that they're developing correctly.) Each eye has six tiny muscles surrounding it, which are designed to work in unison, enabling the eye to turn full circle. However, like many muscles throughout the body, sometimes one or more of these eye muscles is weaker than the others. This results in one eye not being able to turn as well as the other eye. If one eye is weaker than the other, the image in the weaker eye is blurred and the visual pathways in the brain don't develop properly. This can result in blindness or reduced vision. The good news is that this is nearly always preventable. Here's how:
Do a home eye test.
Shine a (not-too-bright) light into your baby's eyes and notice the "light reflect" (the tiny white dot that shows in the middle of each eye). When your baby is looking directly at the light, the light reflects should be in the center of each eye. This indicates that the eyes are straight. The tiny white dot should remain in the center of the eye as you move the light from side to side and around in a circle as your baby follows it. If, however, you notice that the white dot is in the center of one eye and off to either side of the other eye, your baby's eyes may be crossed. It's common for a baby's eyes to occasionally appear crossed when baby is particularly tired, but it's still important to mention what you noticed to your pediatrician at your baby's next scheduled checkup.
Rule out pseudo strabismus.
With a condition called pseudo strabismus, the eyes appear crossed but really aren't. This quirk usually occurs in infants who have a wide nasal bridge. The whites of these babies' eyes show less than in babies with a narrower nasal bridge, giving the illusion of crossed eyes.
Seek treatment early.
If your doctor suspects that your baby's eyes are truly crossed, the next step will be a referral to a children's eye specialist or pediatric ophthalmologist. The specialist will do a more thorough eye exam and test the strength of each eye muscle. If a crossed or lazy eye is detected, the doctor will recommend treatment to strengthen the weak eye muscles and develop the visual pathways in the brain. This usually involves wearing a patch over the stronger eye to force the muscles in the weaker eye to work harder. Sometimes glasses or eye drops can be used to blur the vision in the stronger eye—another way to force the use of the weaker eye. As a last resort, surgery can correct the weakened muscles.
While you should always discuss any concerns with your pediatrician, remember that most of the time crossed eyes in infants will straighten out by six months of age without treatment.