The eye contains a jelly-like substance called the vitreous. Shrinking of the vitreous usually causes the hole. As a person ages, the vitreous becomes thicker and stringier and begins to pull away from the retina. If the vitreous is firmly attached to the retina when it pulls away, a hole can result.
Most of the eye’s interior is filled with vitreous, a gel-like substance that fills about 80 percent of the eye and helps it maintain a round shape. The vitreous contains millions of fine fibers that are attached to the surface of the retina. As we age, the vitreous slowly shrinks and pulls away from the retinal surface. Natural fluids fill the area where the vitreous has contracted. This is normal. In most cases, there are no adverse effects. Some patients may experience a small increase in floaters, which are little “cobwebs” or specks that seem to float about in your field of vision.