Do Eyelids Tighten Up As They Heal After Blepharoplasty?

The swelling goes down over time as the eyelids heal, but the real reason the eyelids tighten is because the surgery removes the excess skin and treats the tissue. It’s really the surgery that makes the eyelids tighten, not the healing process.

On ocassion, with the swelling postop, this exerts extra weight on the lower lids causing it to pull down or away from the globe (eyeball). Over time, as the swelling subsides, this should improve. If not, then it may need to be addressed. Good luck with your recovery. 

At 4 weeks, the wounds are still healing and remodeling, so it may improve/tighten with time. Conservative measures such as artificial tear drops or punctal plugs inserted by your ophthalmologist, may help keep the surface of the eyes moist. If the irritation is only when showering, consider baby shampoo (which is better tolerated if suds hit the eye).
So long as the corneas are not showing signs of damage or infection, nothing aggressive is indicated for the moment. After several months, if the lids are pulling away or down, a simple suture in the outside corner (canthopexy or canthoplasty) usually helps, but depends on your eye exam findings. Transconjunctival blepharoplasty can also cause similar symptoms early after surgery.