What causes the lightening of eye color from childhood into young adulthood in an individual born with dark brown eye color, resulting in a final adult eye color of light hazel?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 1, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Research

Eye color can naturally lighten from dark brown to hazel from childhood to adulthood due to changes in melanin production, a process that is primarily genetic and developmental. This transition typically occurs within the first few years of life but can continue into adolescence, as supported by a study published in 1997 1. The final eye color is determined by multiple genes that control melanin production and distribution in the iris.

Some key points to consider:

  • Most babies are born with darker eyes because melanin production is not fully established at birth.
  • As a child grows, melanin levels in the iris can decrease, causing the eyes to gradually lighten to their genetically predetermined adult color, which may be hazel.
  • Environmental factors like lighting conditions can also affect how eye color appears, making hazel eyes seem to change color depending on surroundings.
  • This lightening process is completely normal and doesn't require any medical intervention, unless the eye color changes suddenly in adulthood, which could indicate a medical condition requiring evaluation by an eye care professional.

It's worth noting that a more recent study published in 2020 2 provides a comprehensive review of the molecular and biochemical mechanisms of human iris color, but the key takeaway remains that genetic and developmental factors play a crucial role in determining eye color.

In terms of morbidity, mortality, and quality of life, it's essential to prioritize regular eye exams to detect any potential issues early on, as highlighted in a study published in 2016 3. However, this is more relevant to the detection of conditions like cataracts, rather than the natural lightening of eye color.

Overall, the lightening of eye color from childhood to adulthood is a normal process that does not require medical intervention, unless accompanied by other symptoms or sudden changes in adulthood.

References

Research

Eye color changes past early childhood. The Louisville Twin Study.

Archives of ophthalmology (Chicago, Ill. : 1960), 1997

Research

Value of Routine Eye Examinations in Asymptomatic Patients.

Optometry and vision science : official publication of the American Academy of Optometry, 2016

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.