This famous optician is full name Abu Sad Al-Ala ibn Sahl. He is a very spectacular scientist. His discovery of the law of refraction of light greatly influenced the development of science, especially in the field of optics. Before Western scientists discovered the facts about refraction of light, Ibn Sahl had succeeded in revealing it first.

The Muslim Muslim physicist was born in 940 AD and died in 1000 AD. He was a scientist who devoted himself to the palace of the Abbasid Caliph in Baghdad.

His success in the field of optics proved that he was a great scientist in the golden age of Islam. This one scientist recorded three important sciences, namely optics, mathematics, and physics. However, according to Len Berggren, Ibn Sahl also mastered geometry.

The law of refraction of the findings was set forth in a treatise he wrote in 984 AD with the title On Burning Mirrors and Lenses or Burning Mirrors and Lenses. In the treatise, Ibn Sahl studied mirrors and convex lenses and hotspots. Ibn Sahl also discovered the law of refraction or refraction which he described mathematically. He uses the law of refraction of light to take into account the shapes of lenses and mirrors whose focal points are at a point on the axis. About 600 years later, Snell, a Dutch scientist also revealed the same thing. According to Snell, the beam came, the line was normal, and the refractive ray was located on one flat plane. This is one of the facts that shows that Muslim scientists have first discovered important findings in the treasures of science.

Howard R. Turner in his book titled Science in Medieval Islam also acknowledged that optics is an original discovery of Muslim scholars. “This science is the scientific finding of the most original and most important Muslim scholars in Islamic history,” he said. According to Turner, Ibn Sahl was the first Muslim scholar to study optical science with high and systematic quality of research.

The success of Muslims in mastering optics in the Caliphate began with the hard work of philosophers, mathematicians, and health experts who studied the fundamental nature and workings of view and light. In the ninth century AD, Muslim scientists diligently explored and studied the works of Greek scientists, such as Euclid’s work, as well as treatises by Egyptian astronomer Ptolemy about optics. The history of modern optics often mentions the name Ibn Haitham, in the period of 965-1039 AD, as the “Father of Modern Optical Science”. Apparently, Ibn Haitham was much influenced by Ibn Sahl. The hard work of Ibn Sahl was able to produce a new understanding of the reflection of light and the principles of visual perception.