Whether it is very hot or not so hot, please use your sun-glasses while travelling in daytime. It will protect your eyes from ultra-violet rays.
Please do not hesitate to take a cap or umbrella while going out during daytime in summer period. Protect your eyes by wearing them. Rather than the black-umbrellas, it is known that light-coloured umbrellas can protect the eyes from ultra-violet rays in a better manner.
Always keep a bottle of drinking water bottle handy while going out! Drink at least 2 litres of water everyday. Taking sufficient water ensures proper moisture level for the eyes.
After returning home, dip cotton bit in water or rosewater and keep them on your closed eyes for a short period. Even cut pieces of cucumber can be kept on the eyes.
There is a trend to apply sun-screen lotions on the skin to protect from heat. However, it is better to ensure that these creams do not touch/rub the eyes.
In order to reduce the excess body heat generated during summer, please take cold & nutritious food which would reduce the body heat.