We rejoice with you that by the grace of the Lord Jesus Christ, you have found someone to accompany you to your colonoscopy. It is a comfort to know that God provides helpers in times of need, and we thank Him for this provision. Remember the words of the Apostle Paul, For we are God's fellow workers. You are God's farming project, God's building. According to the grace of God which was given to me, as a wise master builder I laid a foundation, and another builds on it. But let each man be careful how he builds on it. (1 Corinthians 3:9,10 WEB)
Regarding your eyesight, we understand your concern and fear. It is normal to feel this way, but we encourage you to cast your anxiety on the Lord, for He cares for you. Draw near to God, and He will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double-minded. Lament, mourn, and weep. Let your laughter be turned to mourning, and your joy to gloom. Humble yourselves in the sight of the Lord, and He will exalt you. (James 4:8-10 WEB).
Even in this situation, God is sovereign. He may not remove the physical affliction, but He can provide you with His peace and the strength of character to endure. However, we do not always understand the reasons, but His plan is perfect. We are reminded that, For my thoughts are not your thoughts, neither are your ways my ways, says the Lord. For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts. For as the rain comes down and the snow from the sky, and doesn't return there, but waters the earth, and makes it bring forth and bud, and gives seed to the sower and bread to the eater; so is my word that goes forth out of my mouth: it will not return to me void, but it will accomplish that which I please, and it will prosper in the thing I sent it to do. (Isaiah 55:8-11 WEB).
This is also an opportunity for you to seek Him or ask about His will. God is more than able to provide you with employment. Remember that, But seek first God's Kingdom, and His righteousness; and all these things will be given to you as well. (Matthew 6:33 WEB).
We will be praying for wisdom for you, that through this situation you can glorify God, help others, and be His witness to others. It is also important to study and meditate on His word, for it is a lamp to your feet, and a light for your path. (Psalm 119:105 WEB)
Join us in prayer:
Heavenly Father, we come before You in the name of Jesus Christ, lifting up our brother/sister in need. We thank You for providing a helper for the colonoscopy, and we ask for Your guidance and protection during the procedure. Lord, we also bring before You the concern about his eyesight. We ask for Your healing touch, but more importantly, we pray that You will draw near to him, fill Him with Your grace and strength, and allow him to feel Your peace that passes all understanding. Help him to trust in You and glorify You in this situation. We pray that You will open the doors of employment without the need of sight, and that You will grant guidance, wisdom, and grace. In Jesus' name, Amen.
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
