"SPF is a log measurement of protection against the sun's rays. Although you may be led to believe that a higher SPF sunscreen will give you better protection, the difference in effectiveness between a lower and higher SPF lotion is not much.
For example, the difference in the efficacy between an SPF 15 and 30 sunscreen is just 1.2 percent," Nitin S. Walia, consultant, dermatology at Max Super Speciality Hospital, told IANS.