Combine oats, milk, yogurt, chia seeds, honey, and vanilla in a bowl and mix thoroughly until smooth and evenly blended.
Mash half the blueberries and mix with lemon juice and honey to create a flavorful layer.
Layer oats and blueberry mixture in jars, starting with oats, then blueberries, then oats again for balanced flavor.
Add whole blueberries on top for texture and freshness.
Cover and refrigerate overnight to allow the oats to soften and thicken properly.
Stir before serving and adjust consistency with milk if needed, then add toppings of choice.