Week 15: Light Sensitivity - When Baby First Sees

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Visual System Development

Week 15 brings remarkable developments in your baby's visual system. While the eyelids remain fused shut, the retina is becoming sensitive to light. If you shine a bright light on your belly, your baby may actually move in response to it!

The optic nerve is developing, creating the pathway that will eventually carry visual information from the eyes to the brain. Blood vessels are forming within the eye, and the lens is becoming clearer. Though your baby won't open their eyes for several more weeks, the foundation for sight is being established.

Limb Proportions Normalize

Your baby's arms and legs are reaching more normal proportions relative to the body. The legs, which have been shorter than the arms, are now growing rapidly to catch up. Your baby can move all joints and is becoming more active, though you probably won't feel these movements for a few more weeks.

Hearing Development Begins

The tiny bones of the middle ear are hardening, and your baby may begin to hear some sounds from outside the womb. Loud noises might cause your baby to startle, and they're definitely hearing the constant rhythm of your heartbeat and the sounds of your digestive system.

Scalp Hair Pattern Emerges

The pattern of hair growth on your baby's scalp is becoming established this week. While the hair won't be visible for several more weeks, the follicles are determining where and how your baby's hair will grow. Some babies will be born with full heads of hair, while others will be nearly bald – both are completely normal!

Your Baby's Size

Your baby now measures about 10.1 cm (4 inches) from crown to rump and weighs approximately 70 grams. Your baby is now about the size of an apple and growing rapidly. The body is becoming more proportioned, though the head is still relatively large.

Increased Appetite

Many women notice increased appetite during week 15 as morning sickness subsides and energy returns. This is your body's way of ensuring adequate nutrition for your growing baby. Focus on nutrient-dense foods that provide the building blocks for healthy development.

Recipe: Vision-Supporting Carrot Ginger Soup

Ingredients

• 1 lb carrots, peeled and chopped
• 1 inch fresh ginger, grated
• 1 onion, diced
• 2 cups low-sodium vegetable broth
• 1 can coconut milk (light)
• 1 tbsp olive oil
• Salt and pepper to taste
• Fresh cilantro for garnish

Instructions

1. Sauté onion in olive oil until softened
2. Add carrots and ginger, cook for 5 minutes
3. Add broth and simmer until carrots are tender
4. Blend until smooth, stir in coconut milk
5. Season with salt and pepper
6. Garnish with cilantro
7. Rich in beta-carotene for eye development

Sources:

1. Lagercrantz, H., et al. (2016). The Newborn Brain
2. Hepper, P.G. (2005). Unravelling fetal behavior
3. Sadler, T.W. (2019). Langman’s Medical Embryology