Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
What are rods and cones in the retina of an eye? Why is our night vision relatively poor compared to the night vision of an owl?
Rods and cones are the two kinds of light-sensitive cells in the retina of the eye.
Rods are the rod-shaped cells present in the retina of an eye which are sensitive to dim light and are vital for vision at night.
Cones are the cone-shaped cells present in the retina of an eye which are sensitive to bright light or daylight.
Our night vision is relatively poor compared to the night vision of an owl due to the presence of a relatively small number of rod cells in the retina of our eyes. Nocturnal animals like owl have a relatively large number of rod cells in their retina.
Explanation
The retina of our eye contains a large number of light-sensitive cells that respond to light. These specialized cells are known as photoreceptors.
There are two different types of photoreceptors present within the retina:
1. Rods - They are most sensitive to light and dark changes, hence function better in low light conditions (twilight vision) and get bleached quickly in bright light. They are not good for color vision. There are about 120 million rods found in the human retina.
2. Cones - They are not as sensitive as rods for light. Therefore, they function better in bright light conditions (daylight vision), and require more photons of light to become activated. It also makes us see colors, along with helps us to differentiate between various colors. That's why we are unable to see color very well in dark places. Thus, they are used for color vision and for detecting fine details. There are about 6 million cones found in the human retina.
144 Views
