Glass shower doors are normally made from tempered glass. This means that if they were to shatter, they would break apart into very small pieces, which is safer than large chunks of glass that could impale you. However, for seniors who have balance and endurance issues, glass shower doors can be more dangerous if they were to crash into them. For that matter, shower curtains can also be more dangerous because they would not break a fall. The safest option in a shower is a tile wall.