Lazy Eye

Lazy Eye

Lazy eye or amblyopia is the term given to a situation in which a person fails to see to a normal level with one (or sometimes both eyes) even when wearing the correct prescription. This is generally caused in two possible ways

1. When one eye has a very different prescription from the other and is not corrected with glasses, the blurred image in that eye will be suppressed and the person will see blurred initially, even when glasses are given.  This is refractive amblyopia
2. When the eye is turned (strabismus) and pointing in a different direction to the fellow eye, the brain will suppress the image of the central part of the retina of this eye so that the person does not experience two different images hovering over each other, or double vision. This is strabismic amblyopia. 

A paper published earlier this year about treating lazy eye with no strabismus concludes that the patients who received optometric vision therapy in addition to the standard treatment of optical correction and part-time patching resulted in greater vision gain in a less time than those patients who received the standard treatment. 

Here’s the link to the paper:

https://bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-022-02246-9

A lazy eye is often much more than an eye that just doesn’t see as sharply as its fellow eye. It also often moves less well, and focuses less well. And of course, the brain has not had the chance to learn to integrate the messages coming from each eye. One thing we know, is that patching really improves the eyesight of a lazy eye. However, it does not actively develop integration between both eyes. This is something that vision therapy actively promotes. 

Special lenses for lazy eye, only at LedermanVision 

As I have explained, sometimes a lazy eye happens the prescription in that eye is so different from the other eye. For example, a 5 yr. old has an eye exam and they discover that the right eye has a prescription of +5.00 and the left has a prescription of +0.50. The left will see well and the right eye is lazy. If you give the full prescription to the right eye of +5.00, and do a lot of patching, the eyesight will improve. This does NOT mean that the prescription will change, but that the patient will see better that eye with the glasses. However, when the prescription is so different the patient will feel quite uncomfortable and might even see double when they look away from the center of the lens e.g., when reading.  The other issue is that because the prescription of the lenses is so different, the dimensions of the image on the retina are quite different. This creates a situation which makes it hard for the brain to really fuse the two images into one.

As a result of this, many optometrists and ophthalmologists prescribe a lens that is significantly less strong than the full strength to avoid those problems. For example, in our case +3.00 would be the most that would be prescribed. The down side is that it limits the degree to which the eyesight can be improved because the less power is not optimal.

At LedermanVision we have been using the advanced technology of SHAW lenses designed by Peter Shaw in Canada. Using algorithms in their design, these specially-designed lenses enable me to give the full prescription to the patient. This is because they

1. Make the image dimensions almost the same for each eye even though the lens powers are different
2. Dramatically reduce the problems associated with having lenses of such different powers. 

For the patient that means

• No double vision. 
• No discomfort. 
• Maximum improvement in eyesight. 
• Most binocular experience

With these specially designed lenses that we order in specially, we have been able to help patients in ways that have been impossible without them.

Without these specially designed lenses, treatment options are limited and this impacts directly on the patient’s ability to maximize the development of their visual system. And that impacts on their daily function, especially in the classroom!