Are the claims made by health-related websites about the absence of health harms from masturbation, and the accuracy of this information, true?

What has been published about masturbation is incorrect. Dr. Muhammad Mughawiri mentions in his book "For Men Only" that masturbation causes many problems, including: weakened eyesight, lack of concentration, poor memory, congestion of the reproductive tracts, and it may even lead to a problem in marriage, which is the inability of the man to engage in marital relations. Allah Almighty has not forbidden anything except that there is harm in it. And when He, the Exalted, said: (But whoever seeks beyond that – then those are the transgressors), we learned that there is no good in masturbation because its doer is among the transgressors.