Extreme close-up of a realistic human eye

Extreme close-up of a realistic human eye, iris fully visible, natural texture and reflections. Begin with the eye fully visible, then continuously zoom straight into the black center of the pupil, keeping the iris faintly visible at 50% opacity throughout. As the zoom progresses, reveal a cosmic scene inside the pupil: galaxies, nebulae, and stars. The zoom must be smooth and continuous, no zooming back out, no cutting away, iris always slightly visible to preserve the eye's identity. Cinematic lighting, photorealistic, 8k detail.