What is one eye smaller than the other when i smile?

When one eye appears smaller than the other when you smile, it is due to a few factors:

1. Muscle Dominance: Everyone's facial muscles are different, and some people have more dominant muscles on one side of their face than the other. This can cause one eye to appear smaller when smiling.

2. Eye Shape: The shape of your eyes can also be a factor. Some people have naturally hooded or droopy eyelids that can affect the appearance of their eyes when smiling.

3. Aging: As we age, our skin loses elasticity, and the muscles around our eyes weaken. This can cause one eye to droop slightly more than the other, especially when smiling or showing other facial expressions.

In most cases, having one eye appear smaller than the other when smiling is not a cause for concern. However, if you experience sudden changes in the appearance of your eyes or any other issues with your vision, it's important to speak with a healthcare professional.