The hyaline septal cavity is small and does not need to be filled with food. Under normal circumstances, there is no lumen in the hyaloid septum, which is a tissue membrane that exists during embryonic life and gradually becomes a bilateral peri-lateral diaphragm that divides the lateral ventricle into two parts, the left and the right, as we grow older. In normal individuals there is no obvious lumen in the hyaline septum, both have a potential lumen that is not observed on imaging, and the two membranes are tightly packed together. Some patients may have developmental abnormalities that result in a cavity between the two sides of the hyaloid diaphragm that can be observed on imaging, called the hyaloid septal cavity, which is a developmental abnormality and does not require treatment, much less a small hyaloid septal cavity and how to go about treating it. If the hyaline septal cavity continues to increase in size, it may indicate the presence of internal cysts, which should be followed up, and if the cysts produce pressure symptoms on the surrounding area, surgical treatment should be considered.