HealthTap Online Primary Care Doctors Accepting New Patients
Book a video visit
HealthTap
Telehealth
A member asked:

How come when im in bathroom and lights are of my pupils are big but the second i cut the lights on there tiny i watch them change ?

A doctor has provided 1 answer

Normal response.: When lights are off, pupils enlarge to allow more of the ambient light to hit the retina so you can see a little better in the darkness. When lights are on, you don't need as much light entering the eyes to see, so the pupils constrict.

Dr Russo agreed

Answered 6/22/2015

3.7k views

Thank

Related Questions

A member asked:

My 5 month old has small pupils. They are totally equal in size, respond to light and definitely get bigger, but they just never get really big. Dr checked her eyes and said it's fine, it's just her and she has very light eyes. Ok?

A doctor has provided 1 answer

A member asked:

My eye has a gold ring around the pupil, and all my colors are changing(i see white as pink and others are changed). I cut my cornea a few years back.

A doctor has provided 1 answer

A member asked:

The cornea in my left eye won't focus. The pupil doesn't become big and small like it's supposed to. What could be wrong?

A doctor has provided 1 answer

A member asked:

I'm not on my period and when i went to use the bathroom i found a small clump of blood. What could that mean?

A doctor has provided 1 answer

A member asked:

Best way to clean a cut with things you would normally find in a bathroom?

A doctor has provided 1 answer

Sponsored Content
HealthTap Medical Group does not endorse products or services. Sponsored content revenues support our mission to make health information free and accessible to all.Learn more

People also searched for:

Started Cymbalta 3 days ago. Today vision feels odd, strained. Then I noticed pupils looked really dilated, in bright bathroom. Normal? Should I stop?
I'm not a big water drinker. When I do drink water it causes freak visits to bathroom. If I start drinking more water will this eventually change?
Small lump on lower back. Changes size sometimes and have had it for a few years. When going a lot to the bathroom, it bleeds. It doesn't hurt.
After i eat no matter what it is heavy/light, small/big portion, I am nauseous, belly pains, bathroom, throw up, gas, for past two weeks.
I'm wondering how small and big can the pupil get?

Telemedicine

Primary Care
Manage Your Conditions
Women's Health
Children's Health
Men's Health
Senior Health
Wellness, Prevention & Lifestyle
Sexual Health
Mental & Behavioral Health
Travel Medicine
Urgent Care
Ask your question
Didn't find what you're looking for?

90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.

Ask your question

More of what we treat

Allergies
Antibiotics
Asthma
High Blood Pressure
Prescriptions
Type 2 Diabetes
Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.
HealthTap
HIPAA logo
HIPAASecure
Soc 2 Type 2 logo
SOC 2 Type 2Certified
JCAHO Accredited
JCAHOAccredited
Member App

Download HealthTap

Video visit and message your doctor

Member App QR Code
Play Store Member LinkApp Store Member Link

Questions?

+1 (888) 828-0841support@healthtap.com
LinkedInTwitter
HomeTermsPrivacyCookiesDMCAHealth TopicsDoctors DirectoryDoctor Q&A by Specialty
Copyright 2026 HealthTap, Inc.