Dragon senses

Additional Dragon Rules Dragon Senses (Ex): Dragons have darkvision 120 ft. and blindsense 60 ft. They see four times as well as a human in dim light and twice as well in normal light.

Frightful Presence (Ex): A dragon’s frightful presence has a range equal to 30 feet × the dragon’s age category, but otherwise functions as detailed in the Universal Monster Rules.

Spells: A dragon knows and casts arcane spells as a sorcerer of the level indicated in its specific description. Its caster level depends on its age, as shown for each type.

Spell-Like Abilities: A dragon’s caster level for its spell-like abilities is equal to its total Hit Dice.

Damage Reduction: Dragons gain damage reduction as they age, as indicated on each dragon’s specific entry. Their natural weapons are treated as magic weapons for the purpose of overcoming damage reduction.

Immunities (Ex): Every dragon is immune to sleep and paralysis. In addition, a dragon is immune to one or two additional forms of attack no matter what its age, as given in its description.

Spell Resistance (Ex): As dragons grow older, they become more resistant to spells and spell-like abilities, as indicated in the dragon descriptions. A dragon’s SR is equal to 11 + its CR.