Design and Size: Children's glasses are typically smaller in size than adult glasses to fit the dimensions of a child's head.  This includes frame designs that are often more lightweight and sturdy to accommodate a child's level of activity and head size.

Material: Children's glasses are often made of more durable materials, such as special protective lenses and frames that are soft and resilient to reduce the risk of damage.

Lens Characteristics: Children's lenses may require special designs to account for the developmental needs of a child's vision.  This might include lighter lenses to reduce weight and special anti-glare coatings to minimize glare.

Safety: Children's glasses need to consider safety aspects for everyday use, such as avoiding sharp edges and special frame designs to prevent eye injuries.

Comfort: Designing for comfort is typically a priority for children's glasses, considering the inconvenience of long-term wear for a child.  This could involve using softer nose pads, more comfortable earpieces, and so on.

In conclusion, children's and adult glasses differ significantly in terms of design, safety, lens characteristics, and comfort to suit the unique growth and activity needs of children.  Therefore, choosing appropriate glasses is crucial for a child's visual health.  It is advisable to seek guidance from a professional optical store or doctor when selecting glasses for a child.