Everything that exists and the principle that makes it possible for us to see them is daylight. Daylight shapes people's perception of reality and is free as long as people do not lose their reality. Freedom can only exist in our own mind, in our own field, in the relationship we establish with ourselves. The individual who loses this relationship moves away from the real world. In the project, reference was taken from Plato's cave metaphor. The concept of light that Plato is talking about also reveals a new understanding of freedom for people. Light introduced people to the real world, and the chained people in the cave were able to become free thanks to the reality they could reach. Today, there are situations similar to Plato's cave allegory. Only images and space are changing. For example, spending a long time in closed areas that do not receive any sunlight or limited light as in the cave causes the hormonal balance of the people to be disturbed and they are adversely affected physically and mentally. The longer the time spent in the indoor area and the more limited the interaction of space and daylight, the more distant the individual is. He tries to exist in a virtual world. Therefore, the individual becomes alien to himself and loses his essence. Prison is one of the places where individuals who are disconnected with their self are found the most. Execution systems developed for the individual to remain alone and question himself and his truths make it impossible for the individual to find his own truth and truth with limited light intake. Diseases and anxiety such as anxiety, low self-esteem, tension, anger and depression occur in the individual who has lost his self over time. For this reason, suicide rates are very high in prisons. It is possible that prisoners in prison do not experience such psychological problems by not losing their mental connection with the outside world thanks to sufficient daylight. The relationship between daylight prisoners in F-type prisons in Turkey is limited to high-security closed. Unlike open prisons, security measures are more stringent in F-type closed prisons, and the enforcement system is based on the principle that isolation of prisoners is isolated. In the project, Kocaeli high security F type closed prison was taken as reference and the inadequacy of the prisoners' exit to the courtyard was seen as a problem. Limiting the time to the courtyard to 1 hour and living in a room in the remaining hours as a prison has minimized the communication of prisoners with the outside world. This situation affects their psychology negatively. There are single and triple rooms in the F type plan scheme. The triple rooms are 25m2 and two storeys. A single triple room is opened to each courtyard. Single rooms are 10m2. 3 single rooms open to each courtyard. The only place of contact between prisoners and the courtyard is the windows behind the bars. Therefore, prisoners should not only see the courtyard wall through the windows, but feel the sky, which has only connections with the outside world, inside the space. The 8m courtyard wall is too much for the human scale. As a suggestion, slits were opened in the courtyard wall. Reflective and permeable surfaces are added to these slits. Since these surfaces affect the diffusion of light, they play an important role in visual perception. The selection of the permeable material used for the transport of natural light to the space and used in spatial openings is a very important factor in the perception of the space. Acrylic is preferred instead of glass as the permeable surface material. Acrylic is a transparent material that is extremely resistant to breakage. In this way, escape, suicide, etc. that may occur as a result of breakage. security is provided for enterprises. Daylight from the added openings becomes more involved in the space and interacts with the individual trapped between the borders. Metal is preferred as reflective surface material. On reflective surfaces, light reflects reflectively and makes the reflected surface visible. Therefore, under the effect of daylight reflected from the metal surface, the sky can be pulled down to the lower elevations vertically on the courtyard walls. With the permeable surfaces and reflective metals added to the courtyard wall, it is aimed to take the daylight further and to feel the reflection of the sky behind iron glows during the hours when the prisoners inside cannot reach the courtyard. In this way, the individual will not lose its interaction with reality and the outside world.