For severe irregularities, ophthalmologists prescribe scleral contact lenses. Part of these lenses is located in front of cornea and the other part rests on sclera, or white part of the eye. These lenses correct a greater amount of corneal irregularity and are applied for very advanced keratoconus or very irregular shape of the cornea. Since these lenses are slightly larger than regular contact lenses, their insertion and removal techniques are somehow different from the conventional hard lenses. At the beginning, using such lenses may seem difficult but gradually, over time and with practice, everything will become normal.